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Included review availability: Your plan provides up to 10 included reviews per hour; 0 remain after this review. WalkthroughChangesVM-context exceptions now use the owning process or worker global object for uncaught-exception reporting, capture callbacks, exits, and unhandled rejection dispatch. New subprocess tests cover process and worker handling paths. VM exception routing
Suggested reviewers: Priority: ➖ Normal Merge Risk: ⚪ Minimal · up to The VM and worker exception-routing change has no confirmed actionable regression in the available evidence and is ready for normal merge checks. 🚥 Pre-merge checks | ✅ 4✅ Passed checks (4 passed)
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Status: the fix is complete and the review comments are addressed. The PR is ready for a maintainer. CI on the current head finished (build 116311, 179 of 181 jobs passed). It is red on two tests. This PR touches neither, and
Both are reported for triage. The same source change passed a full run before the latest merges from main (build 103060, 181 of 181 jobs). How I reproduced the bug, with release 1.4.0 and with a debug build of main:
The six new children in |
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LGTM — small, well-scoped fix that routes vm-context exceptions through defaultGlobalObject() to reach the thread's process.
What was reviewed:
- Verified
defaultGlobalObject()returns the input unchanged forZig::GlobalObject, so main-realm/worker/ShadowRealm behavior is identical. - Traced
reportUncaughtExceptionAtEventLoop→Bun__reportUnhandledError→bun_vm()(thread-local) →uncaught_exception; none require the passed global to be aZig::GlobalObject. - The removed
uncheckedDowncast<JSDOMGlobalObject>inreportExceptionwas dead — its result was only forwarded to a function typedJSGlobalObject*. - Tests cover all three affected reporting paths (FinalizationRegistry, EventEmitter, EventTarget) plus the capture callback, subprocess-isolated with exact stdout/stderr/exit assertions.
Extended reasoning...
Overview
Two C++ changes plus tests. In Bun__handleUncaughtException (BunProcess.cpp), the early-return when the incoming global is not a Zig::GlobalObject is replaced with defaultGlobalObject(lexicalGlobalObject), and the two downstream uses of lexicalGlobalObject (calling the capture callback and Bun__Process__exit) are switched to the mapped global. In reportException (JSDOMExceptionHandling.cpp), an uncheckedDowncast<JSDOMGlobalObject> — which asserted on debug builds when the listener's realm was a NodeVMGlobalObject — is removed; the raw lexicalGlobalObject is passed on directly. Four new subprocess tests in test/js/node/vm/vm.test.ts.
Security risks
None identified. This is an exception-routing fix; no parsing of untrusted input, no auth/crypto/permissions. Mapping a vm context to the thread's default global is the existing pattern (promiseRejectionTrackerForNodeVM does the same for rejections) and cannot expose anything the context couldn't already reach via the host.
Level of scrutiny
Moderate. Bun__handleUncaughtException is the single sink for uncaught exceptions, so a mistake would affect every error path. However the change is provably a no-op for the existing Zig::GlobalObject case (defaultGlobalObject returns its argument via dynamicDowncast), and only widens behavior for NodeVMGlobalObject from "return false → fatal path" to "deliver to the thread's process" — which matches Node. I traced the downstream Rust path (Bun__reportUnhandledError → global.bun_vm() reads a thread-local, uncaught_exception takes &JSGlobalObject) and confirmed nothing there requires a Zig::GlobalObject.
Other factors
The tests are well-constructed per the repo's review guidance: subprocess-isolated, test.concurrent, exact stdout/stderr/exitCode assertions, and the FinalizationRegistry case polls a bounded window for the observable condition rather than sleeping. The PR description documents verification against Node v26 and 21 upstream node test files. The removed downcast in reportException was genuinely dead (its result was passed to a parameter typed JSGlobalObject*). No prior human reviews or outstanding comments.
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The automated review above raised no action items, so there is nothing to change from it. My own self-review of the diff is still in progress. I will post here if it turns up anything. |
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Updated 9:54 PM PT - Sep 15th, 2026
❌ @robobun, your commit 08c08c8 has 2 failures in
🧪 To try this PR locally: bunx bun-pr 39992That installs a local version of the PR into your bun-39992 --bun |
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While checking the fallback paths for this fix, I found that the same report crashes a worker. The worker's last-resort handler passed the context's global to The two comment-length review threads are addressed in 56584f9. |
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I reviewed this PR and didn't find any bugs. Because it changes the uncaught-exception routing path (Bun__handleUncaughtException, reportException, and the worker's last-resort error dispatch), a human look would still be worthwhile.
What was reviewed:
defaultGlobalObject()semantics — aZig::GlobalObjectmaps to itself, so main/worker/ShadowRealm are unchanged; onlyNodeVMGlobalObjectis newly routed.reportUncaughtExceptionAtEventLooptakesJSGlobalObject*and just forwards toBun__reportUnhandledError, so dropping the deaduncheckedDowncast<JSDOMGlobalObject>is safe.- The worker's
on_unhandled_rejectionnow dispatches onvm.global()(the worker's ownZig::GlobalObject), which is whatWebWorker__dispatchErrorreads fields from. - Tests: six subprocess children, concurrent, drain pipes together, assert exact output before exit code; the FinalizationRegistry case polls a bounded loop and fails visibly if the callback never runs.
Extended reasoning...
Overview
Three tightly-scoped native changes plus a test block:
src/jsc/bindings/BunProcess.cpp:Bun__handleUncaughtExceptionmaps its incoming global throughdefaultGlobalObject()instead of returningfalsefor non-Zig::GlobalObjectrealms. Also swapslexicalGlobalObject→ the mappedglobalObjectfor the capture-callbackcall()andBun__Process__exit.src/jsc/bindings/JSDOMExceptionHandling.cpp: removes a deaduncheckedDowncast<JSDOMGlobalObject>(only fed a commented-out block) and passeslexicalGlobalObjectstraight toZig::GlobalObject::reportUncaughtExceptionAtEventLoop, whose signature is(JSGlobalObject*, Exception*)and whose body just callsBun__reportUnhandledError.src/jsc/web_worker.rs:on_unhandled_rejectionignores the realm global it is handed and usesvm.global()forWebWorker__dispatchError,create_syntax_error_instance, andformat2.test/js/node/vm/vm.test.ts: sixtest.concurrentsubprocess children covering FinalizationRegistry, a process 'exit' listener, an EventTarget listener, the capture callback, and both worker paths (handler present / absent).
Security risks
None identified. This is exception-routing plumbing; no user input parsing, no privilege boundary. The change replaces an uncheckedDowncast (assertion in debug, type-confusion in release) with a safe dynamicDowncast-based mapping, and replaces a segfault path in the worker with the intended dispatch — both strictly reduce risk.
Level of scrutiny
High. This is the one sink for uncaught exceptions (VirtualMachine::uncaught_exception → Bun__handleUncaughtException) and the worker's fatal-error fallback. A regression here changes process exit behavior or crashes workers. That said, the diff is minimal and the mapping (defaultGlobalObject) is the established idiom the codebase uses to find the thread's process from a bare realm — promiseRejectionTrackerForNodeVM already does the same for rejections, per the PR body.
I checked:
defaultGlobalObject(g)atZigGlobalObject.h:914— returnsgif it is aZig::GlobalObject, else the per-thread default. So the main realm, workers, and ShadowRealm (allZig::GlobalObject) behave exactly as before; only aNodeVMGlobalObjectis newly routed. There is no third realm type in Bun that would silently change behavior.reportUncaughtExceptionAtEventLoopatZigGlobalObject.cpp:1036— parameter isJSGlobalObject*, body isBun__reportUnhandledError(globalObject, ...); passing the vm-context global here is fine and matchesJSCTaskScheduler.cpp:124.uncaught_exceptionatVirtualMachine.rs:1531— whenBun__handleUncaughtExceptionused to return 0 for a vm-context global, control fell through to(self.on_unhandled_rejection)(self, global_object, err)with the vm-context global, which in a worker is the crashingWebWorker__dispatchErrorpath the Rust hunk fixes. Both hunks are load-bearing, as the PR states.- The capture-callback
call()andBun__Process__exitnow receive the mappedZig::GlobalObjectrather than the vm context — consistent with the callback belonging toprocess, and covered by thesetUncaughtExceptionCaptureCallbacktest child.
Other factors
- The PR description is unusually thorough: it enumerates every reporting site, every consumer of the realm global downstream, sibling functions with the same guard and why they are unaffected, and out-of-scope ShadowRealm behavior. Node v26 parity was verified for every child.
- The two comment-cop bot threads are resolved (comments shortened in 56584f9).
- Tests follow harness conventions:
bunEnv/bunExe,test.concurrent,Promise.allon stdout/stderr/exited, exact-string assertions before the exit-code check. The FinalizationRegistry child pollsBun.gc(true)in a bounded loop and asserts a sentinel line if it never fires (so the test can't vacuously pass).
I'm deferring rather than approving because the touched path decides process termination and worker crash behavior; a maintainer should confirm that routing every non-Zig::GlobalObject realm to the thread's default process is the intended policy going forward.
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The second automated review found no defects either. It asks a maintainer to confirm the routing policy. For the record, the policy this PR implements is narrow: only a realm that has no process object at all (a Nothing is left open from the reviews. Waiting on CI. |
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Automated review found no bugs. This changes uncaught-exception routing for node:vm contexts (previously print + exit 1, now delivered to process.on('uncaughtException')) and touches the worker's last-resort error handler, so a maintainer should confirm the routing policy before merge.
Checked: defaultGlobalObject() maps a Zig::GlobalObject to itself (main/worker/ShadowRealm behaviour unchanged) and only remaps a NodeVMGlobalObject to the thread's default global. reportUncaughtExceptionAtEventLoop takes a plain JSGlobalObject* and forwards to Bun__reportUnhandledError, so dropping the JSDOMGlobalObject downcast is safe. The worker's on_unhandled_rejection now dispatches on vm.global(), which is what WebWorker__dispatchError expects; the ignored parameter was only ever the realm the error was raised in. The six new subprocess tests cover FinalizationRegistry, EventEmitter, EventTarget, capture callback, and both worker paths.
Extended reasoning...
Overview
The PR routes exceptions reported against a node:vm context's NodeVMGlobalObject to the thread's process uncaughtException machinery instead of returning false (which previously fell through to print-and-exit-1 on the main thread and to a segfault in a worker). Three source changes: Bun__handleUncaughtException in BunProcess.cpp now maps its lexical global through defaultGlobalObject() and uses that mapped global for the capture callback and Bun__Process__exit; reportException in JSDOMExceptionHandling.cpp drops an uncheckedDowncast<JSDOMGlobalObject> (which asserts on debug builds when handed a vm context global) and passes the lexical global straight to reportUncaughtExceptionAtEventLoop; and the worker's on_unhandled_rejection in web_worker.rs dispatches on vm.global() instead of the realm global handed in. Six new subprocess tests in vm.test.ts.
Security risks
None identified. This is error-routing plumbing; no untrusted input parsing, no auth/crypto/permission surfaces. The change makes previously-fatal errors catchable by user handlers, which matches Node semantics — it does not weaken any check.
Level of scrutiny
Medium-high. The mechanical change is small and the defaultGlobalObject() pattern is already the established idiom for reaching the thread's Bun state from a vm context (promiseRejectionTrackerForNodeVM uses it). But it changes the observable behaviour of uncaught-exception handling — code that used to exit 1 will now run user handlers and continue — and it also fixes a worker segfault path. The author explicitly noted the routing policy (only NodeVMGlobalObject, not ShadowRealm) as something a maintainer should confirm. Both of those warrant a human sign-off rather than an automated approval.
Other factors
The tests are thorough (six subprocess children, each verified against Node v26, covering FinalizationRegistry / EventEmitter / EventTarget / capture callback and both worker paths with and without a handler) and the PR description enumerates every reporting site checked and the upstream Node test suites run. The two comment-cop threads about long comments were addressed in 56584f9 and are resolved. I verified defaultGlobalObject(JSC::JSGlobalObject*) at ZigGlobalObject.h:914 returns the argument when it is already a Zig::GlobalObject, so main-realm/worker/ShadowRealm behaviour is preserved; and reportUncaughtExceptionAtEventLoop at ZigGlobalObject.h:194 / ZigGlobalObject.cpp:1036 accepts a plain JSGlobalObject* and only forwards it to Bun__reportUnhandledError, so no downcast is needed there.
…aughtException Bun__handleUncaughtException returned false for a global object that is not a Zig::GlobalObject. The deferred-work runner (FinalizationRegistry callbacks), the native EventEmitter and JSEventListener all report an exception with the realm of the object that raised it. For a FinalizationRegistry or a listener function created in a node:vm context that realm is a NodeVMGlobalObject, so the exception was printed and the exit code set to 1 without the uncaughtException listeners, the monitor or the capture callback running. Map the realm to the thread's default global, which owns the process object, the way promiseRejectionTrackerForNodeVM already does for rejections. reportException no longer downcasts the listener's realm to a Zig::GlobalObject before passing it on; debug builds asserted there.
The worker's last-resort error handler passed the realm the error was reported against to WebWorker__dispatchError, which reads Zig::GlobalObject fields from it. For an exception raised against a node:vm context that realm is a NodeVMGlobalObject, and the worker crashed with a segmentation fault (Worker.cpp:200) instead of emitting the Worker 'error' event.
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Rebased on main (e3bd3e4). The one conflict was in |
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I reviewed this PR and didn't find any bugs. The fix is small and follows the established defaultGlobalObject() pattern (same mapping promiseRejectionTrackerForNodeVM already uses for rejections), and the six new subprocess tests cover each reporting site plus both worker paths. Because it changes uncaught-exception routing and worker error dispatch — critical process-exit paths — a maintainer look would still be worthwhile, particularly to confirm the routing policy for non-Zig::GlobalObject realms.
What was reviewed:
defaultGlobalObject()is identity forZig::GlobalObject(main/worker/ShadowRealm unchanged); onlyNodeVMGlobalObjectmaps to the thread's default global.reportException's removeduncheckedDowncast<JSDOMGlobalObject>was only fed toreportUncaughtExceptionAtEventLoop, which takesJSGlobalObject*and reaches the VM via a thread-local — safe with the vm-context global.on_unhandled_rejectionnow dispatches onvm.global(); on a worker thread that IS the worker'sZig::GlobalObject, so the main-realm path is unchanged and the vm-context crash is fixed.- The
call()/Bun__Process__exit()swap toglobalObjectruns the capture callback in the realm that ownsprocess, matching Node.
Extended reasoning...
Overview
Four files: Bun__handleUncaughtException in BunProcess.cpp now maps its incoming global through defaultGlobalObject() instead of returning false for a non-Zig::GlobalObject; reportException in JSDOMExceptionHandling.cpp drops an uncheckedDowncast<JSDOMGlobalObject> that asserted on a NodeVMGlobalObject in debug builds; on_unhandled_rejection in web_worker.rs dispatches on vm.global() instead of the realm global it is handed (which WebWorker__dispatchError reads as a Zig::GlobalObject and segfaulted on); and six new subprocess tests in vm.test.ts.
Security risks
None identified. This is error-routing plumbing; no untrusted input parsing, no auth/crypto, no new user-reachable API surface.
Level of scrutiny
Moderate-to-high. The diff is small (~15 production lines) and mechanical — defaultGlobalObject() is the standard idiom used throughout the bindings for exactly this case, and promiseRejectionTrackerForNodeVM already routes vm-context rejections the same way. But the code path is uncaught-exception delivery and worker error dispatch, which decides process exit codes and whether user handlers run. I traced each change: defaultGlobalObject() is identity for a Zig::GlobalObject, so the main realm, workers, and ShadowRealm are unchanged; reportUncaughtExceptionAtEventLoop takes a plain JSGlobalObject* and only calls Bun__reportUnhandledError, which reaches the VM via bun_vm()'s thread-local, so passing the vm-context global there is safe; and on a worker thread vm.global() is the worker's own global, so the Rust change is a no-op except when the passed-in global is a vm context (the crash case).
Other factors
The PR body documents extensive verification (Node v26 parity for every new test child, ~40 upstream test-worker-*/test-process-* files run clean, CI green on build 103060). The comment-cop threads about long comments were addressed and resolved. The tests follow harness conventions (test.concurrent, drained stdout/stderr/exitCode in one Promise.all, bounded poll for the FinalizationRegistry callback rather than a bare sleep, exact-output assertions). The one open item is a policy confirmation — that a vm context's uncaught exception should reach the thread's process — which the PR argues from Node parity and existing precedent, but is worth a maintainer's explicit sign-off given it governs process exit behavior.
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A fuzz run reached the debug assert in
Four shapes, each
All 8 runs (4 shapes, main thread and worker) assert before and pass after. On release 1.4.3-canary.1+6a92015fc the listener object shapes are not assert-only: on the main thread they print the error and exit 1 without running the handler, and in a worker all four end with |
…a node:vm context (#42521) ### Problem - A `PerformanceObserver` whose callback was created in a `node:vm` context crashes the process when it delivers entries. Release 1.4.2 and canary: `panic(main thread): Segmentation fault at address 0x18`. Debug: `ASSERTION FAILED: !source || is<Target>(*source)`, `uncheckedDowncast [Target = Zig::GlobalObject, Source = JSC::JSGlobalObject]`. Node v26.3.0 delivers. - `JSPerformanceObserverCallback::handleEvent` (`JSPerformanceObserverCallback.cpp:63`) casts `callback->globalObject()` to `Zig::GlobalObject` with no check and builds the wrappers for the observer and the entry list from it. `JSCallbackData::invokeCallback` (`JSCallbackData.cpp:53`) repeats the cast to read `scriptExecutionContext()`. The global of a context is a `NodeVMGlobalObject`. It has neither. ### Fix - Both sites map the realm through `defaultGlobalObject()`. A `Zig::GlobalObject` maps to itself. A context maps to the default global of the thread. - Correct because that global owns `PerformanceObserver`, so the wrappers come from the realm of the class. Node also builds the entry list in the main realm. The callback still runs in its own realm. - Verified: new case in `test/js/node/perf_hooks/perf_hooks.test.ts`. It fails on canary (segfault) and on a debug build of main (assertion). Notes lists the other suites. ### Background - The main realm and each worker have a `Zig::GlobalObject`. It holds the DOM wrapper structures and the `ScriptExecutionContext`. `vm.createContext()` makes a `NodeVMGlobalObject`, a bare realm without them. - A context has no `PerformanceObserver`. A test runner or a sandbox hands it the host class, so the callback is a function of the context's realm. - `defaultGlobalObject(global)` (`ZigGlobalObject.h:898`) returns `global` if it is a `Zig::GlobalObject`, else the default global of the thread. Other bindings already use it for contexts. <details><summary>Notes</summary> Repro from the report (`bun p.js`). Confirmed here on 1.4.3-canary.1: exit 139. The report has the same on release 1.4.2. Node v26.3.0 prints `survived, entries seen: 1`. ```js const vm = require("vm"); const ctx = vm.createContext({ PerformanceObserver, performance }); vm.runInContext(` new PerformanceObserver(list => { globalThis.seen = list.getEntries().length; }).observe({ entryTypes: ["mark"] }); performance.mark("hello"); `, ctx); setTimeout(() => console.log("survived, entries seen:", vm.runInContext("globalThis.seen", ctx)), 100); ``` The same crash from the host side, all confirmed on 1.4.3-canary.1 before the fix and delivered after it: - `new PerformanceObserver(vm.runInNewContext("(function(){})")).observe({ entryTypes: ["mark"] }); performance.mark("x")` - the same with the `PerformanceObserver` class of `node:perf_hooks` (it extends the global class and passes the callback to it) - `observe({ type: "measure", buffered: true })`, which delivers before `observe()` returns and not from a task The new test runs these four shapes in one child. For each one it checks that the callback is not an instance of the host `Function`, that `this` and the second argument are the observer, that the list is an instance of the host `PerformanceObserverEntryList`, and the entry names that `list.getEntries()` returns inside the context. Node v26.3.0 prints the same JSON for the child script. In a worker, the default global is the global of the worker (`Bun__getDefaultGlobalObject` reads a thread-local). Checked by hand on the fixed debug build: a context callback inside a `worker_threads` Worker gets a list that is an instance of the `PerformanceObserverEntryList` of the worker. Not in this PR: a context callback that throws. `handleEvent` then calls `reportException` with the realm of the callback, and `reportException` (`JSDOMExceptionHandling.cpp:61`) has the same cast. A debug build asserts there (checked on the fixed build). In a release build that cast compiles to nothing, so the exception takes the reporting path that #39992 describes. #39992 removes the cast and routes the exception to `process`, for this path and for the `EventTarget` listener path. This PR leaves the call as it is so that the two do not overlap. `JSAbortAlgorithm.cpp:33` and `:64` have the same unchecked cast. They are not changed. Its callbacks are never user functions: `startPipeToOperation` (`JSStreamPipeToOperation.cpp:581`) passes a bound builtin made in the global of the stream, and `$addAbortAlgorithmToSignal` has no caller in `src/js`. Suites run with the fixed debug build (ASAN, assertions on), all pass: `test/js/node/perf_hooks/perf_hooks.test.ts`, `test/js/node/vm/vm.test.ts`, `test/js/web/workers/performance-observer-leak.test.ts`, `test/js/deno/performance/performance.test.ts`, `test/js/web/abort/`, `test/js/web/streams/pipeTo-signal-leak.test.ts`, `test/js/web/streams/pipeTo-shutdown-gc.test.ts` (the abort algorithm of `pipeTo` goes through `JSCallbackData::invokeCallback`). Upstream files, all exit 0: test-performanceobserver-gc, test-performance-measure, test-performance-measure-detail, test-performance-function-async, test-perf-hooks-timerify-basic, test-perf-hooks-timerify-error, test-perf-hooks-timerify-constructor, test-perf-gc-crash, test-net-perf_hooks, test-http-perf_hooks. The child script of the new test also runs clean with `BUN_JSC_validateExceptionChecks=1`. </details> <!-- robobun:evidence:begin --> --- **[human-review]** gate passed · iteration 0 · 3 files touched <details><summary>fails on main (without fix)</summary> ```console ASAN without fix: 1 FAILED $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" test/js/node/perf_hooks/perf_hooks.test.ts bun test v1.4.3 (6a92015) test/js/node/perf_hooks/perf_hooks.test.ts: (pass) stubs [17.49ms] (pass) doesn't throw [49.64ms] (pass) Symbol name argument throws V8 wording [14.02ms] (pass) measure(name, optionsWithoutStartOrEnd, endMark) honours the trailing endMark [6.73ms] (pass) timerify entry shape [95.69ms] (pass) timerify is exposed on both performance and as a top-level export (Node v25.2+) [3.17ms] (pass) export surface matches Node v26.3.0 [11.30ms] (pass) timerify and createHistogram survive Object.prototype option pollution [511.64ms] (pass) timerify and AsyncResource.bind survive Object.prototype.get pollution [701.65ms] (pass) net entries are instanceof PerformanceEntry [496.08ms] (pass) re-wrapped native entries, timing and observer keep JS identity [20.26ms] 279 | env: bunEnv, 280 | stdout: "pipe", 281 | stderr: "pipe", 282 | }); 283 | const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]); 284 | expect(stder ... (truncated) release without fix: 1 FAILED bun test v1.4.3-canary.1 (6a92015) test/js/node/perf_hooks/perf_hooks.test.ts: (pass) stubs [0.06ms] (pass) doesn't throw [0.14ms] (pass) Symbol name argument throws V8 wording [0.11ms] (pass) measure(name, optionsWithoutStartOrEnd, endMark) honours the trailing endMark [0.09ms] (pass) timerify entry shape [1.06ms] (pass) timerify is exposed on both performance and as a top-level export (Node v25.2+) [0.03ms] (pass) export surface matches Node v26.3.0 [0.12ms] (pass) timerify and createHistogram survive Object.prototype option pollution [9.42ms] (pass) timerify and AsyncResource.bind survive Object.prototype.get pollution [10.13ms] (pass) net entries are instanceof PerformanceEntry [7.02ms] (pass) re-wrapped native entries, timing and observer keep JS identity [0.29ms] 279 | env: bunEnv, 280 | stdout: "pipe", 281 | stderr: "pipe", 282 | }); 283 | const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]); 284 | expect(stderr).toBe(""); ^ error: expect(received).toBe(expected) - "" + "============================================================ + Bun Canary v1.4.3-canary.1 ( ... (truncated) ``` </details> <details><summary>passes on PR (with fix)</summary> ```console ASAN with fix: all passed $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" test/js/node/perf_hooks/perf_hooks.test.ts bun test v1.4.3 (6a92015) test/js/node/perf_hooks/perf_hooks.test.ts: (pass) stubs [13.18ms] (pass) doesn't throw [35.30ms] (pass) Symbol name argument throws V8 wording [10.58ms] (pass) measure(name, optionsWithoutStartOrEnd, endMark) honours the trailing endMark [5.53ms] (pass) timerify entry shape [54.00ms] (pass) timerify is exposed on both performance and as a top-level export (Node v25.2+) [2.02ms] (pass) export surface matches Node v26.3.0 [8.04ms] (pass) timerify and createHistogram survive Object.prototype option pollution [405.22ms] (pass) timerify and AsyncResource.bind survive Object.prototype.get pollution [508.57ms] (pass) net entries are instanceof PerformanceEntry [418.48ms] (pass) re-wrapped native entries, timing and observer keep JS identity [15.11ms] (pass) PerformanceObserver delivers entries to a callback created in a node:vm context [611.63ms] (pass) mark/measure toJSON and inspection include detail without perf_hooks being loaded [931.56ms] 13 pass 0 fail 76 expec ... (truncated) release with fix: all passed $ bun scripts/build.ts --profile=release [configured] bun-profile → bun (stripped) target linux-x64-gnu build type Release build dir ./build/release revision 558e6ee features baseline 23 deps, 131 codegen, 1172 objects in 687ms ninja: Entering directory `/workspace/bun/build/release' [1/1244] install /workspace/bun bun install v1.4.3-canary.1 (6a92015) Checked 22 installs across 61 packages (no changes) [9.00ms] [2/1244] install /workspace/bun/packages/bun-error bun install v1.4.3-canary.1 (6a92015) Checked 1 install across 2 packages (no changes) [1.00ms] [3/1244] gen bindgenv2 [4/1244] install /workspace/bun/src/node-fallbacks bun install v1.4.3-canary.1 (6a92015) Checked 111 installs across 104 packages (no changes) [8.00ms] [5/1244] gen ErrorCode+*.h [6/1244] gen node-fallbacks/react-refresh.js Bundled 1 module in 11ms react-refresh.js 4.81 KB (entry point) [7/1244] fetch libjpeg-turbo [libjpeg-turbo] up to date [8/1217] fetch tinycc [tinycc] up to date [9/1216] fetch zlib [zlib] up to date [10/1216] gen .bind.ts → GeneratedBindings.cpp [11/1216] gen bake.{client,server,error}.js -> bake.client.js, bake.server ... (truncated) ``` </details> <details><summary>diff hotspot</summary> ``` src/jsc/bindings/webcore/JSCallbackData.cpp | 3 +- .../webcore/JSPerformanceObserverCallback.cpp | 3 +- test/js/node/perf_hooks/perf_hooks.test.ts | 86 ++++++++++++++++++++++ 3 files changed, 90 insertions(+), 2 deletions(-) ``` </details> **gate history** · 1 passed · 0 rejected · iteration 0 <details><summary>evidence per changed file</summary> ``` file reads edits tests src/jsc/bindings/webcore/JSCallbackData.cpp 1 1 6 …/jsc/bindings/webcore/JSPerformanceObserverCallback.cpp 1 1 6 test/js/node/perf_hooks/perf_hooks.test.ts 2 1 6 ``` </details> **root cause** · written by the author bot The callback delivery path in `JSPerformanceObserverCallback::handleEvent` and `JSCallbackData::invokeCallback` took the callback's own global object and unchecked-downcast it to the Bun global, which is invalid when the callback was created inside a `node:vm` context, since a `NodeVMGlobalObject` is a `Bun::GlobalScope` rather than a `Zig::GlobalObject`. Reading the wrapper caches and script execution context off that mis-typed pointer produced a segfault in release builds and a downcast assertion in debug builds. Both cast sites now route through `defaultGlobalObject(callback->globalObjec… <!-- robobun:evidence:end -->
…ught-exception-process # Conflicts: # test/js/node/vm/vm.test.ts
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Merged main to clear the conflict. The head is now 7d2bec9, on main at 877a3f9. The only conflict was in Checked with a debug ASAN build: The first merge took main at f937cf4, where CI can still show one failure that this diff does not cause: |
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The latest automated reviews have one optional item: two test comments described the earlier behavior. Commit 08c08c8 removes those sentences, and the thread is resolved. No other action items are open. The branch now includes main up to 877a3f9. The diff against main is still the same four files. I built that head with the debug build and ran the six new tests again: all pass. About the red run on the previous head (build 116295): the only test that failed on every lane was |
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LGTM — the comment cleanup from the previous round is in, and the three native edits are small and consistent with each other.
What was reviewed:
Bun__handleUncaughtException: every downstream use of the global (processObject(),getVM, the capture-callbackcall, bothBun__Process__exitsites) now uses thedefaultGlobalObject()result; aZig::GlobalObjectmaps to itself, so main-thread, worker, and ShadowRealm realms are unchanged.- Thread affinity of the fallback:
Bun__getDefaultGlobalObjectreads a#[thread_local]set per VM (Bun__setDefaultGlobalObjectruns for worker globals too), so a worker's context maps to the worker's own process, which the two worker children assert via the parent-side monitor. - The other
on_unhandled_rejectionimplementations (default_on_unhandled_rejection, run_command's before-close handler) ignore the realm argument, andBun__Process__exitresolves the VM from the thread, so no sibling site still depends on the lexical global being aZig::GlobalObject. reportException: the removeduncheckedDowncast<JSDOMGlobalObject>fed only aJSGlobalObject*parameter, so dropping it changes no behavior beyond removing the unsound cast.
Extended reasoning...
Overview
The PR touches three native sites and one test file. src/jsc/bindings/BunProcess.cpp replaces an inherits(Zig::GlobalObject::info()) early-return in Bun__handleUncaughtException with defaultGlobalObject(lexicalGlobalObject) and switches the two remaining lexicalGlobalObject uses (the capture-callback call and the Bun__Process__exit(…, 1) after a throwing capture callback) to the resolved global. src/jsc/bindings/JSDOMExceptionHandling.cpp drops an uncheckedDowncast<JSDOMGlobalObject> and a commented-out block, passing the lexical global straight to Zig::GlobalObject::reportUncaughtExceptionAtEventLoop, which only forwards to Bun__reportUnhandledError. src/jsc/web_worker.rs makes the worker's on_unhandled_rejection dispatch on vm.global() instead of the realm it was handed. test/js/node/vm/vm.test.ts adds six spawned children covering FinalizationRegistry, process.on('exit'), EventTarget listeners, the capture callback, and two worker variants. The only change since the prior review is commit 08c08c8, which removed the two "used to" sentences flagged in the earlier nit.
Security risks
None identified. The change affects where an already-uncaught exception is delivered (the owning thread's process object rather than being dropped or crashing); it introduces no new parsing of untrusted data, no new allocations, and no new privilege or network surface. The worker fix removes a segfault path (reading Zig::GlobalObject fields off a NodeVMGlobalObject), which is a memory-safety improvement rather than a risk.
Level of scrutiny
Moderate: uncaught-exception routing is runtime-critical, so I traced every consumer of the global that the change rewires. defaultGlobalObject() (ZigGlobalObject.h:900) returns the input when it is already a Zig::GlobalObject, so the main realm, workers, and ShadowRealms are identity-mapped and their behavior is unchanged. The fallback Bun__getDefaultGlobalObject reads a #[thread_local] CACHED_GLOBAL_OBJECT that Bun__setDefaultGlobalObject populates for every global created through the standard creation paths (ZigGlobalObject.cpp:551 and :680), so on a worker thread a context maps to the worker's global, not the main thread's — the concern the REVIEW.md "never back per-VM state with thread-locals" rule is about does not apply here because the cached value is intentionally per-thread and each worker has its own VM on its own thread. Bun__Process__exit resolves the VM via bun_vm(), which is thread-based and works with any global. The remaining on_unhandled_rejection implementations (default_on_unhandled_rejection, on_quiet_unhandled_rejection_handler_capture_value, run_command's before-close variant) ignore the global argument; the jest handler does use it but is reached before Bun__handleUncaughtException via the isBunTest short-circuit and is unchanged by this PR. In reportException, the removed downcast produced a pointer that was only ever passed as JSGlobalObject*, so removing it is behavior-preserving apart from eliminating the assertion in debug builds.
Other factors
The test block uses test.concurrent.each, spawns with bunEnv, drains stdout/stderr/exit concurrently, and asserts exact stdout plus empty stderr, so each assertion can fail; the FinalizationRegistry case's Bun.sleep(1) sits inside a bounded poll loop and the "never ran" fallback line would break the exact-stdout match rather than pass silently. The parent-side uncaughtExceptionMonitor in the worker children doubles as a negative check that the exception did not reach the main thread. No CODEOWNERS entry covers the changed files, no human reviewer has requested changes, and the bug hunt ran dry. The one prior nit from this reviewer was addressed in the latest commit, and no new concerns surfaced, so approval is appropriate.
… and CLI (#46021) ### What does this PR do? Hardening. This collects the open pull requests that fix a crash in Bun into one change, and fixes about 20 more crashes that had no pull request. "Crash" here means a segfault, a Rust panic, an abort, a failed assertion, memory corruption that a sanitizer reports, a native stack overflow, or an exception that ends the process and that the program can't catch. With this PR those cases throw a normal error, print a normal CLI error and exit 1, or just work. 306 pull requests are included: 227 whole, and 79 cut down to the crash fix where the rest was a refactor, a feature or a behavior change. Each one was checked against current `main` first. 45 more turned out to be fixed already, and 17 were duplicates. The full list is at the bottom. #### Crashes you could hit in normal use - **`bun build` with macros and a `.env` file crashed at random.** In a repro with many macro modules, more than a third of the builds crashed. Now 3,000 of 3,000 produce the right bundle. (#45960) - **`bun run` and `bunx` aborted if a signal arrived while the child was being spawned.** (#38926, #45965) - **`bun build --compile ./index.js ./public/*` panicked** if an embedded file's name wasn't valid UTF-8. - **A truncated or corrupted compiled executable** died with SIGBUS or a panic at startup. It now prints an error. (#31787, #38251, #41360) - **Dev server:** several `Option::unwrap()` panics after a failed or deleted import (#38046, #44744, #44746), a segfault when an `onLoad` plugin throws while another bundle is queued, a request that hung and then panicked with `bundle active`, and `server.stop()` that never resolved after a client aborted a waiting request. - **`Bun.serve`:** `server.fetch(url, { headers: new Headers() })` followed by a GC segfaulted (#40888). Routes were used after free after `server.reload()` with `tls.serverName` (#38636). - **`text()` and `json()` on a stream of string chunks** could abort the process, a regression in 1.4.0. (#44269) - **`Bun.Transpiler` with `exports.eliminate` or `exports.replace`** aborted on `export default 1` and on most re-export clauses. (#44137) - **A decorated `declare` field in a class expression** with `experimentalDecorators` panicked. (#38095) - **YAML and JSON5 files with a key that isn't a string** panicked with `--no-bundle` and in `Bun.Transpiler`. (#41827) - **`Bun.FileSystemRouter`:** reading `.params` segfaulted when a rejected route candidate left its parameters behind. (#39290, #39291) - **Native addons that call `uv_async_*`, `uv_timer_*`, `uv_idle_*`, `uv_prepare_*`, `uv_check_*`, `uv_queue_work` or `uv_cwd`** aborted with "unsupported uv function" on Linux and macOS. They're implemented now. (#36609, #39652, #39892) - **`--watch` and `--hot`** panicked when the system was out of inotify instances or file descriptors, or when the reload `exec` failed. They print an error now. (#39629, #39975, #44837) - **Paths longer than the path buffer** panicked in `bun install`, the resolver, the bundler, `--compile`, `tsconfig.json` `paths` and `baseUrl`, `package.json` `main` and `sideEffects`, `bun run --filter`, `bun pm diff`, source maps and snapshots. They're ordinary errors now, or they work. (#36340, #37529, #39104, #39650, #43067) - **A Worker that creates a `ShadowRealm` and imports `node:worker_threads` in it** segfaulted. - **`structuredClone` or `postMessage` of an X25519 key** gave an object that aborted the process when read. (#45624) - **`node:stream` web adapters and `node:http2`** could end the process with an exception that no handler could catch. (#45076, #45975) - **Windows:** a watcher panic in a burst of file changes (#44344), a segfault after the machine resumes from sleep (#33015), crashes in the shell's pipe reader (#39638, #43606), and addons that import from `node.exe` without the delay-load hook (#35618). Most of the rest needs unusual input: strings near the 2 GiB limit, buffers that another thread or a getter resizes or detaches in the middle of a call, `worker.terminate()` at a bad moment, running out of memory or file descriptors, very deep nesting, or hostile arguments to `bun:ffi`, `node:vm` and `bun:sqlite`. #### Behavior changes Things that didn't crash before and behave differently now: - `new` on native functions that aren't constructors throws a `TypeError`, as in Node: `util.types.*`, `buffer.isAscii`, `isUtf8`, `transcode`, `resolveObjectURL`, `bun:jsc` exports, `cc()` symbols. It used to return the call's result. They also stop printing as `[class hostname]`. (#34575) - `` $`cmd` `` throws `ERR_INVALID_ARG_VALUE` if an environment variable's name or value contains a NUL byte. It used to cut the value at the NUL. (#44981) - `cc()` functions throw a `TypeError` for arguments that used to reach C as garbage, and `read.*(ptr, NaN)` throws. (#37989, #38057, #40773) - As PID 1, `bun` exits with 128 + the signal number on Ctrl+C or `docker stop`. (#38877) - A `NODE_MODULE` addon that's already loaded by the main thread throws `ERR_DLOPEN_FAILED` when a live Worker loads it too, as in Node. (#39968) - An exception from a `node:vm` context reaches `uncaughtException` handlers. (#39992) `vm.constants.DONT_CONTEXTIFY` returns the real global proxy. (#34623) - `createPrivateKey` rejects an EC JWK whose private value doesn't match its public point. (#33752) - `@dec static {}` is a syntax error, as in TypeScript and esbuild. (#44883) - `clearTimeout` ignores 0 and negative ids, and timer ids no longer wrap. (#44771) - HEAD for a `Response` whose body is an S3-backed `Blob` reports the length that GET sends. (#44734) - `bun:sqlite` and `node:sqlite`: if `iterate()` left a write unfinished on a connection that has a hook, a user function or an authorizer, the write is finished on the connection's next call instead of during garbage collection. If the database is gone too, it's rolled back. - `bun test --bail` runs exit listeners and closes SQLite databases. (#39010) - Dev server: a request for a client script waits while a bundle is in flight (#42733), query strings reach framework routes (#33232), and a request gets a 500 instead of hanging when plugins fail (#36812). #### File formats - `.jsc` bytecode files get a 24-byte footer so they can be verified before decoding. Files from an older Bun are ignored and the source is parsed instead. (#39396) - `node:vm` `cachedData` gets an 8-byte checksum. A blob from an older Bun is rejected, which the API allows. (#32839) - The built-in modules section of a compiled executable changes from format 1 to 2 and carries an engine stamp. (#44907) #### Performance Measured in instructions per operation on release builds of this branch and its base, with an A/A run for the noise floor (0.0 to 0.2 %). No change: `Bun.serve`, `node:http`, WebSocket echo and publish, `bun build` of 3,807 modules, `bun run` with 2,000 imports, `readdir` / `Glob` / `fs.cp` over 23,689 entries, startup and RSS. The binary grows by 176 KB (0.17 %). | Faster | Instructions | | --- | --- | | WebSocket echo of a 1 MB non-ASCII text message | −72 % | | `Bun.inspect` of a large non-ASCII string | −39 % | | `Bun.markdown.html` on large non-ASCII input | −33 % | | `` $`cmd` `` with 300 environment variables | −6 % | | `fs.readSync` | −5 % | | `TextEncoder.encodeInto`, short ASCII strings | −4 % | | async `crypto.pbkdf2`, 16-byte inputs | −17 % | | Slower | Instructions | Why | | --- | --- | --- | | `cc()` calls | +5 to +51 per call | Argument count and type checks, and a check for `close()` (#37989, #38057, #43802, #44921). `dlopen()` calls don't change | | `process.env.X = v` | 38 → 593 per write | Writes aren't cached. Reads don't change (#38871) | | async `crypto.pbkdf2`, inputs of 1 KB or more | +4 to +9 % | Password and salt are copied (#40554) | | `bun build` with an object `--define` used thousands of times | +4.5 % | The object is copied per use (#45969) | #### Not included - Fixes that need a WebKit change: #39967, #42534, #42982, #43764, #43786, #44226. #42185 too: a typed array that has no `ArrayBuffer` yet can't be pinned, so `view.buffer.transfer()` during an async call can still free its bytes. Creating the `ArrayBuffer` up front costs 7 to 12 % on every async `fs` call, so the fix belongs in JSC: an `ArrayBuffer` created while the view is borrowed should start out pinned. - #45442 (`calc()` sums as a flat list): it changes minified output for real stylesheets to survive a `calc()` with 25,000 terms. It deserves its own review. - #40023 (Windows event loop redesign), #29928 (Windows exit path), #40534, #43963, #39571, #42904, #42834, #36355, #43266: refactors or features whose crash is already covered or isn't a crash. - The pull requests marked *(crash fix only)* below should stay open for their other half. ### How did you verify your code works? - **Tests.** Every fix has a test that fails on `main` (a release or an ASAN build) and passes on this branch, except where that isn't practical: code that only runs on Windows or macOS, inputs that need several GB of memory, and a few rare races. Those were checked by hand or by reading. - **Stored repro scripts.** 230 crash repros ran on release and ASAN builds of this branch and of `main`, side by side. Release: 88 no longer crash. ASAN: 106 no longer crash. None crashes that didn't before. What still crashes needs WebKit, is SQLite's own bug, or isn't a crash. The ASAN number is from a later commit than the release number. - **Dev server.** Because one fix makes requests wait, 2,171 generated programs ran random interleavings of edits, build errors, failing plugins, reloads, stops and disconnects with about 120,000 requests. No request hung, was answered twice or got a stale body. `main` hung in 82 of 1,161 programs. This also found the four dev server bugs listed above. - **Path helpers.** 336,000 boundary cases with buffers of exactly the computed size, and 12,003 random calls through 30 JS APIs on an ASAN build, compared with `main`. No sanitizer report, and the results match wherever `main` doesn't panic. - **What worked on 1.4.3 still works.** Reviewers compared behavior with 1.4.3 and took out what changed it: for example an output directory layout change for 9 or more entry points, a `server.reload()` change, and a changed error message for `import("file:///50%deposit.ts")`. - **Not run locally:** the Windows, macOS and FreeBSD code paths. CI compiles and tests them. ### Included pull requests **Bundler, transpiler, CSS, macros** (33) - #33881 bundler: allocate wrapper_ref for CommonJS modules with no non-hoistable statements - #35055 Bun.build plugins: handle filter RegExp flags beyond i/m/v - #37769 bundler: fail the build instead of panicking when the bundle thread cannot create its waker - #37784 bundler: copy inlined env values into the define arena, and give each Bun.build its own env copy *(crash fix only)* - #37858 bundler: fail the build instead of panicking when a plugin answer string cannot be converted - #38046 bun build --server-components: require the bun target and reject directives without a framework *(crash fix only)* - #38095 js_parser: fix panic on decorated declare/abstract fields in class expressions with experimentalDecorators - #38966 bundler: keep deep CSS, export star and composes graphs from overflowing the linker's stack - #38984 bundler: stop an export star ambiguity that loops back into a re-export chain from overflowing the stack - #39113 css: reject stylesheets of 2 GiB or more instead of aborting on an int cast - #39396 bundler: frame .jsc bytecode sidecars and verify them before decoding - #39855 bundler: join the work still on the pools before the bundle is torn down *(crash fix only)* - #41157 dev server: leave out an html link to a cached json module instead of panicking, and mark a new placeholder file stale - #41801 css: decode ill-formed UTF-8 to U+FFFD before tokenizing *(crash fix only)* - #41827 bundler: handle YAML and JSON5 keys that are not strings instead of panicking - #42242 js_parser: compress symbol link chains when following merged declarations - #42387 bundler: check receivers on the Bun.build plugin object and freeze its filters during a build - #42413 Bounds-check the InternalSourceMap window reader - #42657 macros: keep visited values alive so a reused address does not get another value's Expr - #43330 transpiler: do not print an empty `var` for a data file with no named export - #43355 bundler: fix "The memory limit has been exceeded." on large HTML entries - #43658 react-compiler: fix skipped functions and build aborts for dead code in a try body *(crash fix only)* - #44137 js_parser: fix four crashes of exports.eliminate and exports.replace - #44467 js_parser: replace skipped expressions with E::Missing and skip argument checks after a stack overflow - #44662 js_parser: walk binary chains on the heap and check the stack when rewriting decorated #private accesses - #44712 json5: reject sources of 2 GiB or more before parsing instead of aborting on an int cast - #44864 js_parser: walk conditional chains in import()/require() and define keys in a loop - #44883 js_parser: reject a decorator on a class static block, keep decorators out of the body of `declare global` *(crash fix only)* - #45045 Fix a segfault in new Bun.Transpiler(): re-point options.log after the constructor moves its Log - #45604 css: keep a url() in an at-rule prelude as written, and never print the resolved path of a url() *(crash fix only)* - #45748 bundler: put --banner/--footer in the bytecode ESM module record (flags from a parse, entries from JSC) *(crash fix only)* - #45960 macros: give each parse-worker macro VM its own env loader - #45969 js_parser: copy object and array defines per use, and copy the list of a lone JSX spread object *(crash fix only)* **`bun build --compile` and standalone executables** (3) - #31787 Don't crash at startup when a standalone executable's embedded graph is corrupted *(crash fix only)* - #38251 compile: exit with an error instead of SIGBUS when a standalone executable is truncated - #41360 standalone: check every offset in the embedded module graph before reading it **Resolver, module loading, plugins, paths** (25) - #32269 Bun.plugin: validate the namespace without a shared regex - #33183 bun:jsc: filter internal cells out of getProtectedObjects() - #34575 Don't register native functions as their own constructors - #36340 paths: size the thread-local join output buffers to MAX_PATH_BYTES on Windows - #37037 mock.module: reject async factory results that are not objects - #37065 bun:jsc: propagate JSONParse exceptions from samplingProfilerStackTraces - #37529 resolver: don't abort on a package.json sideEffects entry longer than the join buffer - #38179 node:module: throw instead of crashing when module._compile is set to a non-function - #38273 bun test: report a test file or preload the loader cannot resolve instead of exiting; keep the JUnit report valid U… *(crash fix only)* - #38732 paths: compute the common path of 9+ inputs with the same loop as fewer *(crash fix only)* - #39228 paths: strip C:\\ down to the drive root in without_trailing_slash_windows_path *(crash fix only)* - #39650 bun run --filter: stop panicking on workspace paths longer than the path buffer - #40186 resolver: stop deeply nested exports targets from overflowing the stack - #40258 resolver: publish Entry.abs_path through the per-entry mutex - #42183 node:module: reject a _resolveFilename override result that contains a null byte - #42401 node:module: accept any `this` in Module.prototype.require *(crash fix only)* - #42405 Bun.plugin: transpile a copy of typed array onLoad contents - #42414 node:module: end the Module._stat path at the first null byte - #42685 resolver: strip the trailing separator inside bust_dir_cache - #42735 Throw a RangeError instead of aborting when require.resolve paths or Worker preload outgrows its Vector - #43067 Report a path that does not fit a path buffer instead of aborting *(crash fix only)* - #44410 Fix a crash when code from a node:vm context reads require.cache or require.extensions - #44466 Trace the value an object or data module exports from its JSSourceCode - #45044 Bun.plugin: give onLoad's args.path its own bytes - #45117 cjs: do not call an `__esModule` getter during the annotation lookup **Dev server, `bun bake`, routers, `--watch` and `--hot`** (28) - #28793 Stop file watcher thread before Global.exit tears down memory *(crash fix only)* - #32143 bake: fix "Runtime file not found" panic in production builds of custom frameworks - #32443 watcher: don't free the Watcher in the spawn-to-start window *(crash fix only)* - #33232 bake: normalize the HTTP request-target before matching framework routes - #36812 bake: respond 500 and release both RequestContext refs when on_plugins_rejected / OOM drains a deferred framework r… - #37039 bake: report per-file print failures in the dev server instead of serving empty modules - #37276 hot_reloader: take entries_mutex for watcher-thread directory cache probes - #37444 bake: unregister Bake::SourceProvider from the source map table when it is destroyed - #39290 FileSystemRouter: match / against a root-level optional catch-all route *(crash fix only)* - #39291 FileSystemRouter: order dynamic routes by per-segment precedence like Next.js *(crash fix only)* - #39629 watch: report a failed watcher init as an error instead of a crash - #41185 bake: check for exceptions in the production build's module loader hooks and helpers - #41340 bake: skip the directory watch when the directory cannot be opened - #41617 Decide a directory watch event from the watchlist, not from the resolver's cached listing *(crash fix only)* - #42547 bake: re-arm the memory visualizer timer when it fires - #42733 dev server: make a client script request wait for the bundle in flight - #42828 bake: serve routes from a router root outside the project root instead of aborting or answering 404 - #42831 bake: resolve app.root and router roots through one checked join - #42836 bake: report route scan errors instead of aborting, and fail bun build --app on them *(crash fix only)* - #42840 dev server: map a router type's server entry point to the root route of that type - #42862 Bun.serve: return before a pending app.plugins setup() settles *(crash fix only)* - #42920 Do not create a mimalloc heap per FileSystemRouter, reload() or :nth-child(An-B) selector - #42934 dev server: register a client component without evaluating it - #43329 dev server: check the route bundle index of a client script URL before Index::init - #44249 fs.watch: read each directory and close it before descending - #44344 Windows: fix a watcher panic and lost events in a burst of file changes, and a --hot that stops watching a deleted… - #44744 dev server: answer a cached-file lookup only for a graph that bundled the file - #44746 dev server: keep an importer in its own graph when an import fails or is deleted **`Bun.serve`, sockets, HTTP, WebSocket, HTTP/2, QUIC, DNS** (28) - #42667 Reland "usockets(windows): keep a closed poll alive until the outer tick and libuv are done with it" (#39643) - #33015 fix(windows): segfault in uv__wake_all_loops after system resume *(crash fix only)* - #35761 node:quic: detach lsquic ctx pointers before the finalize-order sweep at worker VM teardown - #37082 Bun.serve: terminate FIFO/pipe file responses at EOF - #38024 dns: keep the c-ares uv_poll_t alive while its poll callback is on the stack (Windows) - #38636 serve: fix route use-after-free after reload() with tls.serverName *(crash fix only)* - #40888 server.fetch: copy a Headers argument instead of adopting the wrapper's pointer - #41337 Update lsquic to 4.9.4 and free unsent stateless resets on destroy *(crash fix only)* - #41384 usockets: hold a tick level for the whole of close_all - #41412 Windows: wait for close completions when closing a worker's uv loop - #41516 node:http2: handle an empty byte range in respondWithFile and respondWithFD - #41521 udp: report every binaryType from the getter, reject a dgram bind of the other family *(crash fix only)* - #42188 net: do not assert a two-character host in SocketAddress.parse - #42210 libuv(windows): keep a pipe's completed read counted until its read callback returns - #42334 fetch, Bun.serve: throw a RangeError for Headers that total 4 GiB or more *(crash fix only)* - #43738 usockets: close a socket whose resume the kernel refuses from the loop, not from the caller - #44338 node:http: response trailers travel with the end call of the response *(crash fix only)* - #44433 bake: make the parked-request list non-owning and look up the DevServer when a plugin load settles - #44533 node:quic: capture the handshake while the conn is alive, set the application at session creation - #44734 Bun.serve: answer HEAD for an S3-backed Blob body without an S3 stat - #44751 node:quic: close() waits only for opened streams, and lsquic sends no GOAWAY before HTTP/3 starts *(crash fix only)* - #44897 node:http2: throw instead of panic when the native setNextStreamID() misses its argument - #45076 node:http2: let close() and destroy() win over the refusal of a request - #45341 uws: AsyncSocket::write takes a size_t length, so res.end() sends a body of 2 GiB or more whole - #45522 node:http2: throw for an ALTSVC frame that is too long and for a pushPromise id that is not a stream id - #45676 node:quic: do not reset a stream lsquic has already finished - #45822 node:quic: name a stream in queued session events by a per-session key, not by its address - #45858 Bun.serve WebSocket: a message that does not fit in memory fails one connection, not the server *(crash fix only)* **Streams, Blob, S3, files, `node:fs`** (28) - #33845 io: propagate IoRequestLoop init failure instead of aborting *(crash fix only)* - #36365 prompt: drop debug_assert that rejects answers containing CR - #37090 Deliver FIFO bodies whose writer connects after the reader opens *(crash fix only)* - #38039 node:fs: stop fs.copyFile(src, "") from segfaulting on Windows - #38653 shell(cp): reject copying a directory into itself; walk cp trees without recursion - #39207 Convert scope-object receivers in the chaining functions and inspect.custom fallbacks - #39390 Blob deserialize: reject over-long paths, treat size >= MAX_SIZE as unknown, make slice() non-panicking - #39639 fetch: drop the upload and drain hop refs at VM teardown *(crash fix only)* - #40008 inspect hooks: copy user options with putDirectMayBeIndex *(crash fix only)* - #40462 Windows: FileSink.start({ path }) on a live writer: hand the writer a libuv fd and close the old source *(crash fix only)* - #41440 node:fs: pass the buffer to the read/readv/write/writev callback on error - #41584 Walk the timer pairing heap without recursion - #41608 native-readable: accept a stream with no native handle - #41710 JSSink write(): convert the chunk before resolving the native sink *(crash fix only)* - #42711 webstreams: bound the native recursion through a chain of tees or text streams - #43264 fetch: reject a file: URL whose path has an encoded NUL - #43709 s3: fix double free of a multipart part's bytes on worker terminate - #43950 streams: link readers and writers last, reject their promises as handled - #44036 PipeReader: label a chunk Eof only when the reader is at its end - #44181 streams: throw instead of aborting when a direct stream's text sink cannot take a string chunk - #44195 fs: validate POSIX directory records in one parser, report a malformed record as EIO *(crash fix only)* - #44269 streams: join the string chunks of a text consumer with one allocation - #44490 watch(windows): report a failed child spawn as an error instead of a panic *(crash fix only)* - #44954 process.stdout/stderr with no FileSink: write synchronously, reset after a failed write *(crash fix only)* - #45004 streams: leave a stream alone when a consumer fails to lock it - #45521 FileSink: throw ERR_ILLEGAL_CONSTRUCTOR from the constructor that script reaches by writer.constructor - #45738 s3: own the Blob store across the calls that run user JS - #45975 node:stream: do not touch the web controller after the web side is done **Node-API, V8 API, `bun:ffi`, `process.dlopen`** (15) - #36609 napi: implement uv_cwd on POSIX - #37989 bun:ffi: stop cc() from turning non-numeric pointer arguments into garbage pointers - #38057 bun:ffi: make cc() reject non-numeric i64/u64 arguments instead of passing garbage - #38425 bun:ffi: throw on an empty cc() source array instead of panicking - #39652 napi: implement uv_async_t, uv_queue_work and uv_default_loop on posix - #39805 Share one handle scope implementation between Node-API and the V8 API - #39892 napi: implement uv_idle_t, uv_prepare_t, uv_check_t and uv_timer_t on posix - #40144 bun:ffi: return undefined for a NULL napi_value from cc() and throw the scheduled napi exception - #40773 bun:ffi: add the full byteOffset in read.*, do not truncate it to int32 - #41704 napi: hand the thrown value to napi_get_and_clear_last_exception after napi_run_script - #42960 process.dlopen: run a V8 addon's init function after dlopen() returns - #43797 Fix debug assertion on an empty error message from a V8 addon or SQLite *(crash fix only)* - #43802 bun:ffi: throw a TypeError when a cc() symbol is called after its library's close() - #43940 napi: fail with ERR_BUFFER_TOO_LARGE instead of aborting above the ArrayBuffer limit *(crash fix only)* - #44921 bun:ffi: pad a short call to a cc() symbol with undefined **`node:vm`, workers, process, timers** (19) - #34623 node:vm: run DONT_CONTEXTIFY contexts directly against the real global - #32839 node:vm: reject invalid cachedData instead of crashing - #36921 error printer: clear the pending exception when formatting a non-Error uncaught value throws - #37270 error printer: one render per error, [Circular] under the key that closes the cycle - #38740 bun:test: give each VM its own fake clock *(crash fix only)* - #39864 Report a refused HTTP, bundle, IO or process waiter thread as an error instead of a crash *(crash fix only)* - #39992 process: deliver exceptions reported against a node:vm context to uncaughtException - #41654 node:vm: give each SourceTextModule request the import attributes of the declaration that created it *(crash fix only)* - #41739 Do not forward the inherited IPC channel to spawned scripts and tools - #41769 node:vm: stop compiling accepted cachedData, report each cachedData decode to the GC *(crash fix only)* - #42045 bun:test fake timers: never move the fake clock backwards - #42308 process.execve: throw instead of aborting for a string past the string limits - #42734 node:vm: report cachedData of 2 GiB or more as rejected instead of aborting - #42843 process.dlopen: reject a filename of PATH_MAX or more before dlopen() - #43500 process: accept SIGSTKFLT, SIGPOLL and SIGPWR, and emit every name of a signal number *(crash fix only)* - #44486 worker: stop the start sequence when a handler it calls stops the worker - #44771 timers: allocate ids from one 64-bit counter that never wraps - #44837 --hot: defer a reload during the preloads, and report a reload that cannot start - #44991 Fix a use-after-free in the VM ref-string intern for a string over the length limit **Shell, spawn, CLI, `bun test`, `bun install`** (31) - #30642 Fail fast at startup when simdutf has no usable implementation for this CPU - #34223 Fix four crashes: HTMLRewriter disturbed body, S3 locked-stream upload, ConnectionsList closed parser, shell brace… *(crash fix only)* - #34884 Guard the console and test-runner formatters against native stack overflow on deeply nested values *(crash fix only)* - #36584 process.chdir: publish an immutable cwd slice so no thread sees a torn cwd - #37135 bun test --parallel: hold the JSC API lock while draining the worker's final IPC backlog - #37527 shell(mv): report ENAMETOOLONG instead of panicking when a source name does not fit the path buffers - #37528 cli: stop aborting on absolute script paths longer than 1024 bytes on Windows - #38162 shell(cp): report ENAMETOOLONG instead of panicking on operands longer than the path buffers - #38205 shell(windows): report ENAMETOOLONG for operands that do not fit the path buffer - #39010 bun test: exit through the VM teardown path when --bail stops a run - #39104 bun test: report over-long coverage dir, JUnit outfile and bunfig root instead of panicking *(crash fix only)* - #39638 shell(cat): serve a second cat on the same stdin instead of hanging or panicking - #39641 usockets: report an out-of-descriptors event loop init as an error, not a crash *(crash fix only)* - #40181 shell: stop deeply nested if clauses from overflowing the parser stack - #40885 shell: throw instead of panicking when a ReadableStream is used as a redirect - #41155 ipc: send a queue item larger than 2 GiB in capped write requests - #42298 bun:test: print String objects with 16-bit storage correctly - #42577 bun:test: root the return values toHaveReturnedWith collects - #43606 shell(windows): report a failed pipe reader start through on_reader_error instead of leaking the subprocess *(crash fix only)* - #43838 node:cluster: read a worker's `ack` and `addressType` in the primary only when they are int32 - #44172 node:cluster: refuse a descriptor of the wrong kind in the primary *(crash fix only)* - #44185 node:cluster: one handle for each descriptor that workers name *(crash fix only)* - #44491 bun test: run every callback when native code leaves an exception pending *(crash fix only)* - #44694 shell mv: refuse to copy a directory into itself on the cross-device fallback - #44752 shell: take the command-substitution capture and drop its NUL bytes - #44981 shell: reject NUL bytes in .cwd() and .env() at the native setters - #45206 ini: reject a source of 2 GiB or more in Parser::parse instead of aborting on an int cast *(crash fix only)* - #45348 bun test: fix a segfault in .not.toThrow(Class) when Symbol.hasInstance accepts a thrown string, symbol or BigInt - #45649 shell: replace the output counters in mkdir, cp, ls and touch with the OutputTask queue - #45792 bun test: SIGKILL a spawnSync child that is still running 500 ms after the test's timeout *(crash fix only)* - #45910 create: own the remote-template response buffers instead of parking them in the CLI arena **Web APIs, Buffer, encoding, URL, crypto, zlib, SQLite, Redis and the rest** (96) - #29709 console: guard JSX/Proxy recursion in Bun.inspect (stack overflow SIGSEGV) - #30817 console.takeHeapSnapshot: clear prior snapshots before building - #30956 spawnSync: make signal-forwarding register/unregister safe for concurrent callers *(crash fix only)* - #31505 node:zlib: reject invalid brotli flush values at validation *(crash fix only)* - #31735 node:path: fix win32 drive-relative resolve on non-Windows hosts *(crash fix only)* - #32085 Fix crash when RedisClient onclose/onconnect is set to a non-callable - #32240 Fix BroadcastChannel custom inspect crash with numeric option keys - #33181 Reject interior null bytes in Bun.mmap, Glob.scan, and FileSystemRouter paths *(crash fix only)* - #33752 node:crypto: validate EC JWK private scalar matches public point in createPrivateKey - #34976 spyOn: install and restore through one writer that throws when the object refuses *(crash fix only)* - #35562 structuredClone: purify NaN in deserialized Date timestamp so getTime never returns a forged JSValue - #35618 napi(windows): load addons that import node.exe without win_delay_load_hook - #35757 Coerce later arguments before capturing input buffers in Bun.Transpiler and Bun.RedisClient - #37252 Report UTF-16 to UTF-8 encode counts through size_t so exactly 2^32 written bytes doesn't wrap to 0 - #37338 node:module: build require.cache without user-writable globals and propagate its exceptions *(crash fix only)* - #37340 redis: accept unsubscribe acks that arrive outside subscriber mode - #37370 Error.appendStackTrace: make appending an error's trace to itself a no-op - #37443 node:crypto: fix null deref when worker.terminate() lands during an EC JWK private key import - #37448 jsc: check for exceptions before using a stored constructEmptyArray result *(crash fix only)* - #38009 MessagePort: fix a heap-use-after-free in contextDestroyed(), release ref() when the last 'message' listener is rem… *(crash fix only)* - #38469 napi: settle or refuse async work queued during VM teardown instead of taking a ticket - #38708 Handle 16-bit module sources in the error preview, the new-position fix-up and the REPL *(crash fix only)* - #38821 process.env: make a failed env build throw instead of aborting (Windows 0xC0000409 on Bun.$ / Bun.sql / process.env… - #38871 process.env: coerce to string on every execution of an assignment, not just the first - #38877 cli: exit 128 + signo when bun cannot die from a re-raised signal (bun as container PID 1) - #38926 Clear the inherited signal mask at startup and exec children with an empty one *(crash fix only)* - #39382 Make a failed util.inspect load throw from custom inspect functions instead of aborting - #39481 Always create the error when a native error message exceeds the string length limit - #39651 performance: keep the user timing entry counts exact after clearMarks(name) and clearMeasures(name) - #39775 Turn seccomp SIGSYS traps into ENOSYS so the syscall fallbacks run on Android - #39968 process.dlopen: replay a non-context-aware V8 addon only while no other live VM owns it - #39975 watch: report a failed reload exec as an error instead of a panic *(crash fix only)* - #40346 Give Glob's native scan methods their own private names - #40554 node:crypto: copy password and salt for async pbkdf2 and scrypt - #40567 url: reject URL-encoded input over the WTF decode limit instead of aborting - #40577 url: throw a RangeError instead of aborting when URLSearchParams or FormData outgrows its Vector - #41073 Store array-index property names as indexed properties in native object builders - #41137 Write the sampling profiler report at exit from Bun, not JSC's atexit hook - #41365 webview: fail only the view when WebKit lacks initWithDirectory: - #41574 Decode a private copy of a JS buffer in the UTF-8 decoders *(crash fix only)* - #41652 console: read a BigInt depth option by value in console.dir - #41749 Startup: reopen fd 0-2 as /dev/null only when the fd is closed - #41819 Report an incoherent BUN_JSC_* option combination as a configuration error, not a crash *(crash fix only)* - #42158 webview: reject malformed Chrome replies instead of crashing - #42179 shell: clamp a `> ${buf}` redirect to the target buffer's live length - #42187 node:crypto: throw ERR_OUT_OF_RANGE for >2 GiB buffer arguments instead of aborting - #42191 URLPattern: throw instead of aborting when a pattern string passes the string limit - #42192 Copy WebAssembly.Memory bytes for native borrows that outlive the call *(crash fix only)* - #42198 Make Bun.$, Bun.sql, Bun.postgres and Bun.SQL custom value getters so reifying the Bun object passes exception chec… - #42203 node:fs: fs.read into a WebAssembly.Memory view writes into the block a grow freed - #42214 Headers: throw a RangeError instead of aborting when the set-cookie list cannot grow - #42218 Headers: throw instead of aborting when a value passes the string length limit - #42220 URLPattern: throw instead of aborting when the token list cannot grow - #42225 Throw ERR_STRING_TOO_LONG from Bun.wrapAnsi instead of aborting when the output passes the string length limit - #42226 Throw instead of aborting when a MIME string does not fit in a string *(crash fix only)* - #42237 Bun.Cookie: throw instead of aborting when the Set-Cookie string passes the string length limit - #42249 Copy a shared input before libdeflate compresses it in Bun.gzipSync and Bun.deflateSync - #42253 bun test: walk nested describe scopes without native recursion - #42259 Throw instead of aborting when a domainToASCII host passes the string length limit - #42310 Parse a private copy of a shared or resizable buffer in Bun.Transpiler, Bun.markdown, Bun.YAML and Bun.TOML *(crash fix only)* - #42312 YAML, JSON5, XML stringify: throw instead of aborting when the output passes the string length limit - #42318 Bound libdeflate's emit path so a racing input cannot overrun the output - #42338 inspector: check the type of process.argv in getModuleGraph - #42364 node:perf_hooks: do not truncate the monitorEventLoopDelay resolution to int32 - #42412 transpiler cache: reject an entry with no sourcemap section - #42479 worker_threads: do not abort when markAsUntransferable/markAsUncloneable gets a WebAssembly GC reference - #42517 EventTarget: skip a listener object that has no realm - #42518 fs.Stats: make the date accessors define the property like Object.defineProperty *(crash fix only)* - #42575 Stop natives from writing onto a foreign `this` with putDirect: process.ppid, require.cache, StringDecoder, the nat… *(crash fix only)* - #42631 JSStringView: pin the cell that owns the borrowed characters - #42660 bun_core: read /dev/urandom when getrandom(2) answers ENOSYS or EPERM - #42780 node:crypto: treat a name too long to convert to UTF-8 as unknown instead of aborting - #42782 node:crypto: throw ERR_OUT_OF_RANGE for a passphrase larger than INT_MAX bytes - #42856 url: do not abort when a host is too long for the IDNA conversion buffers - #42868 sqlite, console, process: do not abort on a string too long to convert to UTF-8 *(crash fix only)* - #42941 Bun.sliceAnsi: throw instead of aborting when the result passes the string length limit - #43058 Bun.serve: fix crash and cross-request 500 when inspecting a non-Response return value throws - #43904 JSC bindings: build property keys from a BunString through Bun::toIdentifier - #44124 Bun.Image: decode WebP into a Bun-owned canvas and read ICCP without the demuxer *(crash fix only)* - #44190 Convert scope-object receivers before Buffer read*/write* and vm.Script describe them - #44211 Stop getsockname(out), useFakeTimers() and the stream source pull() from writing onto a caller's object with putDirect - #44295 bun test --coverage: append a final newline to a text that lacks one *(crash fix only)* - #44360 rust-argon2: return OutOfMemory instead of aborting when the memory cost cannot be allocated - #44421 node:zlib: free zstd's workers before the dictionary they read - #44521 util.parseArgs: pick the default args start from a per-VM eval flag, as Node v26 does *(crash fix only)* - #44740 structured clone: tolerate a zero-sized shared WebAssembly.Memory in computeMemoryCost() - #44759 HTMLRewriter: park a suspended handler's token before the output flush - #44907 Builtins section format 2: an engine stamp says which buns compile its modules - #45188 Reject an oversized WebCrypto cipher output instead of aborting - #45354 Throw for a `file:` URL whose path is not UTF-8 on Linux and macOS, through one `fileSystemPath()` accessor *(crash fix only)* - #45608 ipc: refuse an over-long message before the receive buffer stores it - #45624 webcrypto: write the key type into the X25519 structured-clone record - #45625 node:sqlite: refuse session.close() and Symbol.dispose inside a SQLite callback - #45653 glob: a group with `?` or a class matches when an alternative takes 64 bytes or more - #45820 Bun.file, S3Client.file and Bun.write no longer keep a buffer path alive forever - #45832 `bun check`: fix a panic on `export *` without a module specifier, and a false error for one in parentheses ### Already fixed on `main`, or duplicates of a pull request above Already fixed: #27323 #30401 #31011 #31206 #31566 #31626 #31695 #31702 #31945 #32773 #34154 #34697 #34744 #34964 #35655 #35816 #36020 #36181 #36296 #36342 #36581 #36602 #36807 #36818 #36857 #37172 #37235 #37239 #37267 #37420 #37731 #37914 #38113 #38119 #38509 #38514 #38540 #38975 #39410 #40749 #41163 #41171 #42108 #43085 #43230 Duplicates: #45654 #29986 #33378 #36895 #37070 #37639 #38014 #39021 #41266 #42250 #42951 #43238 #44259 #45335 #45565 #45726 #45965 Fixes #5019 Fixes #6106 Fixes #10690 Fixes #10886 Fixes #13566 Fixes #14745 Fixes #15551 Fixes #20454 Fixes #21310 Fixes #29145 Fixes #30454 Fixes #30613 Fixes #30766 Fixes #32103 Fixes #32142 Fixes #32183 Fixes #32212 Fixes #39060 Fixes #42296 Fixes #42931 Fixes #43671 Fixes #44201 Fixes #44735 Fixes #44783 Fixes #45198 Fixes #45327 Fixes #45491 Fixes #45721 --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
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This is Claude (an AI assistant) commenting on Jarred's behalf. This fix went in with #46021, which is merged. Closing. |
Problem
node:vmcontext never reachesprocess.on('uncaughtException'), the monitor, or the capture callback. Bun prints it and exits 1. In a worker it crashes instead:Segmentation fault at address 0x101inWebWorker__dispatchError(Worker.cpp:200).Bun__handleUncaughtException(src/jsc/bindings/BunProcess.cpp:1285) returns false when its global is not aZig::GlobalObject. A context's global is aNodeVMGlobalObject. The caller takes false as "no handler" and runs the fatal path, which in a worker readsZig::GlobalObjectfields from that global.EventTargetpath,reportException(src/jsc/bindings/JSDOMExceptionHandling.cpp:61) downcasts the same global. Debug builds assert there.Fix
Bun__handleUncaughtExceptionmaps its global throughdefaultGlobalObject(). AZig::GlobalObjectmaps to itself, so the main realm, workers, and ShadowRealm behave as before. ANodeVMGlobalObjectmaps to the thread's default global, which ownsprocess.src/jsc/web_worker.rs) dispatches onvm.global(), the globalWebWorker__dispatchErrorexpects, not on the realm it is handed.processof its own. The exception can only go to the process of the thread that runs the context.promiseRejectionTrackerForNodeVM(NodeVM.cpp:955) already routes a context's rejections this way. Matches node: every child in the new test prints the same lines and exit codes under node v26.test/js/node/vm/vm.test.ts, six new children, all fail on stock bun. The worker child without a handler still crashes with only the C++ part. Other suites in Notes.Background
Zig::GlobalObject, which holds the Bun state:process, the worker's event scope.vm.createContext()makes aNodeVMGlobalObject, a bare realm with none of that.defaultGlobalObject(global)(ZigGlobalObject.h:914) returnsglobalif it is aZig::GlobalObject, else the thread's default global. Bindings that a context can reach use it to findprocess.VirtualMachine::uncaught_exceptionis the one sink for uncaught exceptions. Reporting sites pass it the realm of the object that threw. It triesBun__handleUncaughtException, then the thread's fallback: print and exit 1 on the main thread, the Worker's'error'event in a worker.Notes
Repro from the report (release 1.4.0 prints the error, exits 1,
reported: 0):Worker crash, release 1.4.0 (
panic: Segmentation fault at address 0x101, the debug build reports the SEGV inWebWorker__dispatchErroratWorker.cpp:200):Affected reporting sites, each with a child in the new test:
JSCTaskScheduler::runPendingWork(JSCTaskScheduler.cpp:119, FinalizationRegistry),EventEmitter::innerInvokeEventListeners(EventEmitter.cpp:268, aprocesslistener created in a context, the test uses'exit'),JSEventListener::handleEventthroughreportException(JSEventListener.cpp:227, an EventTarget listener created in a context, with bothon('uncaughtException')andsetUncaughtExceptionCaptureCallback). Two worker children: with a handler in the worker (handled there, worker exits 0) and without one (Worker'error'event, worker exits 1, the process exits 0). ThereportExceptionchildren fail on a stock debug build by the assertion, on a release build by the exit code. The worker children crash on stock bun.The other consumers of the realm global in
uncaught_exceptionwere checked with a context global on the fixed debug build: the main-thread printer (prints, exit 1, as before),Bun__Process__exit(uses the VM only), and thebun testrunner (the error is charged to the running test, as for a main-realm throw).process._fatalException()called from inside a context now works too, it used to return false.Also checked on the fixed debug build, each matching node v26: a throwing
beforeExitlistener created in a context with a handler installed (handled, exit 0),--unhandled-rejections=strictwith a promise rejected inside a context (delivered with originunhandledRejection), and a ShadowRealmFinalizationRegistrythrow (unchanged: printed, exit 1, see below).Probed and not affected, they pass the main global already:
setTimeout(vmFn)(the timer's global),queueMicrotask(vmFn),process.nextTick(vmFn).Bun__handleUnhandledRejectionandBun__emitHandledPromiseEventhave the same guard and are left as they are. A context's rejections are mapped before they get there, bypromiseRejectionTrackerForNodeVM, andhandleRejectedPromisesruns on theZig::GlobalObjectthat holds the list.Out of scope: a ShadowRealm gets a full
Zig::GlobalObjectand so aprocessobject of its own. A throwingFinalizationRegistrycallback in a ShadowRealm goes to that realm's process, which has no listeners, and exits 1 today.defaultGlobalObject()keeps that unchanged. Routing every realm to the thread's process would be a separate decision.NodeVMGlobalObject's method table entry forreportUncaughtExceptionAtEventLoopis JSC's default no-op. Bun reports throughZig::GlobalObject::reportUncaughtExceptionAtEventLoopdirectly, never through the table, and a context exposes noqueueMicrotask, so the entry is not reachable and is not touched.Suites run with the fixed debug build:
test/js/node/vm/,test/js/node/process/process.test.js,test/js/node/process/process-on.test.ts,test/js/web/abort/,test/js/node/events/,test/js/web/workers/worker.test.ts,worker-terminate-funnels.test.ts,worker-terminate-lifetime.test.ts. Upstream files, all exit 0: the 25test-worker-*files whose names mention uncaught, exit, error, unhandled, or exception, plus test-process-exit-code, test-emit-after-uncaught-exception, test-event-target, test-events-uncaught-exception-stack, test-eventtarget, test-process-exception-capture, test-process-exception-capture-errors, test-process-exception-capture-should-abort-on-uncaught, test-process-uncaught-exception-monitor, test-timers-uncaught-exception, test-uncaught-exception-handler-stack-overflow, test-vm-parse-abort-on-uncaught-exception, test-worker-nested-uncaught, test-worker-non-fatal-uncaught-exception, test-worker-uncaught-exception, test-worker-uncaught-exception-async, test-shadow-realm, test-shadow-realm-gc, test-whatwg-events-eventtarget-this-of-listener.Local noise in this debug ASAN container, all reproduced without the worker change:
script-leak.test.tshits the 5 s default timeout (16 s for 10000 compiles),process.test.jsfails once because the container has noUSERvariable, three timing tests inworker.test.ts(message flood, preload import, fs.readFile terminate) fail on worker startup time, and the c-ares terminate test inworker-terminate-lifetime.test.tsreports a LeakSanitizer leak ofnode_fs_binding::Bindingafter printing itsok.no test proof · iteration 0 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/node/vm/vm.test.ts