meson/ninja/capnp/Go only exist inside the hermetic nix dev shell, but
xce-build.sh never entered it itself -- the /xce-build skill documented
wrapping every invocation in `nix develop ./src --command ...` by hand,
so a bare `bash src/tools/xce-build.sh ...` (run directly instead of
through the skill) failed opaquely with "meson: command not found". This
was a recurring, previously-logged gap that resurfaced again today mid
bug-1789 verification.
The script now checks IN_NIX_SHELL at the top and re-execs itself under
`nix develop` if unset, so every caller -- the skill, a bare invocation,
CI, a human at a terminal -- gets it automatically. A nested call (already
inside the shell) is a no-op past that check. README.md's daily-develop
section updated to match; the old "or use nix develop --command" example
is now redundant and removed.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GLfB5uWRdmx2WiZSFC7Fm7
Rongsong Shen
028d8f6ac7