C: crtl unistd.h misses getpid

• Type: bug / gap (CRTL headers) — Track B/C boundary
• Status: done
• Owner: Track CA
• Found / Opened: 2026-06-27, M5 sqlite bring-up ([[feature-c-desktop-lua-sqlite-path]]), after the sqlite preprocessor defined(...) wall was fixed.
• Closed: 2026-06-27

Symptom

sqlite now advances to:

pascal26:33288: error: call to undeclared function: getpid ()

Repro command:

./compiler/pascal26 -Ilibrary_candidates/sqlite library_candidates/sqlite/sqlite3.c /tmp/sqlite3

Likely Shape

Add the POSIX prototype to lib/crtl/include/unistd.h:

int getpid(void);

The existing C header import path should register it as a libc extern import, matching fsync / sysconf.

Fix

Added int getpid(void); to lib/crtl/include/unistd.h.

Regression

Added test/crtl_unistd_getpid_b101.c, wired into make test-core.

Acceptance

• sqlite advances past getpid at 33288.
• b101 covers getpid.