First attempt used builtins.currentTime at flake-evaluation time -- this
broke the plain, documented `nix build .#xcecore_debug` command entirely
(pure-eval strips builtins.currentTime, requiring --impure) and produced
a raw epoch-seconds string instead of UTC ISO-8601. Caught by task-local
review (REJECTED, round 1) before merge.
Fixed by moving the computation into each derivation's own build phase:
a preConfigure hook in xce.nix/xcecli.nix runs `date -u` (stdenv's
bundled coreutils, unaffected by pure-eval) and appends -Dbuild_time= to
mesonFlagsArray, with a fail-loud guard against empty output. commit_id's
existing self.shortRev/self.dirtyShortRev eval-time mechanism is
untouched. Verified via nix eval (no --impure) and nix build reaching
configure with real values on both xcecore_debug and xcecli (round 2,
APPROVED).
Task 2.2/13 of build-time-versioning. Also corrects design.md/research.md,
which described the now-superseded builtins.currentTime approach.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The dev-loop build path (/xce-build, the one behind the motivating
incident) never set -Dcommit_id= at all, so every locally-built binary
carried an empty commit id. xce-build.sh now computes commit_id (git
rev-parse --short HEAD, -dirty suffixed on uncommitted changes, unknown
fallback on a genuine git failure) and build_time (UTC date), appends
both to MESON_OPTS for every profile before meson setup, and warns
loudly to stderr if either ever resolves empty anyway.
Task 2.1/13 of build-time-versioning.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Add a build_time meson option (string, default '') sibling to the
existing commit_id option, threaded project-wide via the same
add_project_arguments() call that already defines VERSION_COMMIT_ID --
one call, one mechanism, no new plumbing. No consumer wired yet (later
tasks); a plain meson setup with neither option set still configures
cleanly with both defines resolving to empty string.
Task 1/13 of build-time-versioning (spec: .kiro/specs/build-time-versioning/).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
