Smallest Phase 0 module per CLAUDE.md §4 implementation order.
M.chdir(path) returns (true) or (false, errmsg) — errmsg via
strerror(__errno_location()[0]). Glibc errno is thread-local
behind __errno_location() rather than a plain global, hence the
indirect access.
Verified against PHASE0.md §7 expectation: a libc.chdir() persists
across subsequent io.popen() calls (popen's child inherits the
parent's wd), which is the property executor.lua relies on for `cd`
interception. Smoke:
libc.chdir("/tmp"); io.popen("pwd"):read("*l") --> /tmp
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
marfrit
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