fix(godot-cpp): repack.sh for 10.0.0-stable's multi-API layout (+2 reproducibility bugs) - #537

What

tools/godot-cpp/repack.sh cannot build godot-cpp 10.0.0-stable at all, and two of its steps are not reproducible off the machine that produced the current archives. Three fixes, one script.

1. The tag is multi-API now

10.0.0-stable (2026-09-15) dropped the single gdextension/extension_api.json and ships one per engine minor — extension_api-4-3.json … extension_api-4-7.json — and the build picks one. Upstream's own three entry points all say 4.7 for this release: scons api_version= (Makefile, test/SConstruct), cmake GODOTCPP_DEFAULT_API_VERSION (CMakeLists.txt), tools/godotcpp.py::supported_api_versions (4.3 … 4.7). The script hardcoded the single-API path, so it dies with FileNotFoundError on this tag.

It now resolves the file the way the tag itself declares: explicit ENGINE_API argument > the tag's GODOTCPP_DEFAULT_API_VERSION > highest present. Single-API tags short-circuit on the file existing, so nothing changes for them. The generator entry point is unchanged (generate_bindings; with no build profile it is upstream's scons path — generate_trimmed_api("") returns the api as-is and generate_template_get_node defaults to True).

2. The "upstream untouched" check was locale-dependent

It filters diff's Only in <dir>: gen line. On a zh_CN host that line is 只在 <dir> 中存在：gen, so nothing matches and every archive is refused as "upstream files were modified", regardless of content. Now LC_ALL=C diff — pin the message language instead of matching a translation.

3. The archive sha256 depended on the packer's umask

gen/ is created during the repack, so its mode bits (dirs 0o777&~umask, files 0o666&~umask) ride into the archive: umask 002 → 775/664, umask 022 → 755/644. Identical content, different sha256. Non-root extraction of the upstream tarball has the same issue (GitHub's tarballs carry 775/664, extraction under umask 022 yields 755/644), so tar -xzpf takes upstream's modes and umask 002 is pinned for the generated tree. No published byte changes — the two existing archives are the 002 spelling.

Verification (both published hashes reproduce exactly)

tools/godot-cpp/repack.sh godot-4.5-stable 4.5.0         /tmp/out
tools/godot-cpp/repack.sh 10.0.0-rc1       10.0.0-rc1     /tmp/out
tools/godot-cpp/repack.sh 10.0.0-stable    10.0.0-stable /tmp/out
tools/godot-cpp/repack.sh 10.0.0-stable    10.0.0-stable /tmp/out2   # determinism

The new archive was checked from the inside: gen/include/godot_cpp/core/version.hpp = 4.7.0 stable, gdextension/extension_api-4-7.json header = Godot Engine v4.7.stable.official, 1052 generated class headers (vs ~1022 TUs for rc1), and every upstream file byte-identical (gen/ the only addition).

Design notes: .agents/docs/2026-10-17-add-godot-cpp-10.0.0-stable-plan.md.

Deliberately not in this PR (needs org write access)

The 10.0.0-stable version entries can only land once the artifact is downloadable, because CI installs it:

1. publish godot-cpp-10.0.0-stable.tar.gz (sha256 66aaafb6…) to xlings-res/godot-cpp and the gitcode mcpp-res mirror under tag 10.0.0-stable;
2. a v10.0.0-stable tag in mcpplibs/godot-cpp-m (version + compat.godot-cpp dependency bump, hashfuncs.hpp shim re-checked against the 4.7 headers);
3. then the two pkgs/*.lua entries, the tests/examples/ member and the README rows.

I have no write access to either artifact repo, so 3 is a small mechanical change I'm happy to push the moment 1 and 2 are up (URLs + sha256 are known) — or leave it to you if you'd rather do the whole registration yourself, the way 10.0.0-rc1 was done.