fix(cli): preserve claude as argv[0] when spawning the native binary

[snyderra]

Problem

Running Claude Code through happy makes it invisible to anything that identifies the running agent from argv[0].

findGlobalClaudeCliPath() calls resolvePathSafe() (i.e. fs.realpathSync) on every candidate, so on a native install the ~/.local/bin/claude symlink collapses to ~/.local/share/claude/versions/<version>. runClaudeCli() then spawns that path, and argv[0] becomes a bare version number.

Same machine, same Claude Code version, as seen by a terminal workspace manager that labels panes by the agent it detects in them:

$ claude          ->  argv0="claude"     name="2.1.237"   -> detected: claude, idle
$ happy claude    ->  argv0="2.1.238"    name="2.1.238"   -> detected: nothing
                      argv0="node" x3 (happy wrappers)

So the pane shows up as an unrecognized process under a couple of node wrappers. This also breaks plain pgrep claude and status-line integrations that key on the process name. Nothing about the session is actually different -- only the label the OS reports.

Fix

Pass argv0: 'claude' to the spawn in runClaudeCli(). cross-spawn forwards options straight through to child_process.spawn on POSIX, where argv0 is honored, so this is a one-option change with no behavioral effect on the child beyond the reported name.

Skipped on Windows: cross-spawn may route the call through cmd.exe, and overriding argv[0] there would misreport the command actually being run.

Verification

Before/after, spawning a stand-in binary that reports its own process.argv0:

before:  argv0 seen by spawned binary: /tmp/.../versions/9.9.9
after:   argv0 seen by spawned binary: claude

Confirmed on a real session too -- happy claude in a fresh pane goes from undetected to agent: claude, status: idle, and the agent's state (working / idle / blocked) tracks correctly from there.

Tests

Added a regression test to packages/happy-cli/scripts/claude_version_utils.test.ts that stands in for the native binary with a symlink to node (a shell script cannot be used here -- the kernel discards argv[0] for #! scripts) and asserts the spawned process sees claude. It fails on main with the version path and passes with this change.

vitest run --project unit scripts/claude_version_utils.test.ts -> 51 passed.

Note on the existing workaround

HAPPY_CLAUDE_PATH can work around this today, but only if it points at a regular file named claude that execs the real binary -- a symlink gets realpath'd away again by resolvePathSafe(). That is non-obvious enough that it probably should not be the requirement for being visible to a process-based detector.

🤖 Generated with Claude Code