Previously, if the builder exported $VERSION in their environment (as
past Gitian-building docs told them to), but their HEAD does not
actually point to v$VERSION, their build outputs will differ from those
of other builders.
This is because the contrib/guix/guix-* scripts only ever act on the
current git worktree, and does not try to check out $VERSION if $VERSION
is set in the environment.
Setting $VERSION only makes the scripts pretend like the current
worktree is $VERSION.
This problem was seen in jonatack's attestation for all.SHA256SUMS,
where only his bitcoin-22.0rc3-osx-signed.dmg differed from everyone
else's.
Here is my deduced sequence of events:
1. Aug 27th: He guix-builds 22.0rc3 and uploads his attestations up to
guix.sigs
2. Aug 30th, sometime after POSIX time 1630310848: he pulls the latest
changes from master in the same worktree where he guix-built 22.0rc3
and ends up at 7be143a960
3. Aug 30th, sometime before POSIX time 1630315907: With his worktree
still on 7be143a960, he guix-codesigns. Normally, this would result
in outputs going in guix-build-7be143a960e2, but he had
VERSION=22.0rc3 in his environment, so the guix-* scripts pretended
like he was building 22.0rc3, and used 22.0rc3's guix-build directory
to locate un-codesigned outputs and dump codesigned ones.
However, our SOURCE_DATE_EPOCH defaults to the POSIX time of HEAD
(7be143a960), which made all timestamps in the resulting codesigned
DMG 1630310848, 7be143a960e2's POSIX timestamp. This differs from the
POSIX timestamp of 22.0rc3, which is 1630348517. Note that the
windows codesigning procedure does not consider SOURCE_DATE_EPOCH.
We resolve this by only allowing VERSION overrides via the FORCE_VERSION
environment variable.
867a5e172a guix: Register garbage collector root for containers (Carl Dong)
8f8b96fb54 guix: Update hint messages to mention guix-clean (Carl Dong)
44f6d4f56b guix: Record precious directories and add guix-clean (Carl Dong)
84912d4b24 build: Remove spaces from variable-printing rules (Carl Dong)
Pull request description:
```
guix: Record precious directories and add guix-clean
Many users have reported problems that stem from having an unclean
working tree. To that end, I've written a guix-clean script which should
help reset the working tree while respecting user-specified precious
directories.
Precious directories, such as:
- SOURCES_PATH
- BASE_CACHE
- SDK_PATH
- OUTDIR
Should be preserved when cleaning the working tree, and are thus
recorded in ./contrib/guix/var/precious_dirs.
The ./contrib/guix/guix-clean script is able to parse that file and make
sure to avoid them when cleaning out the working tree.
```
ACKs for top commit:
laanwj:
ACK 867a5e172a
Tree-SHA512: c498fad781ff5e6406639df2b91b687fc528273fdf266bcdba8f6eec3b3b37ecce544b6da0252f0b9c6717f9d88e844e4c7b72d1877bdbabfc6871ddd0172af5
By registering the container profiles as garbage collector roots, it
will prevent `guix gc` from garbage collecting derivations which our
container needs and inconvieniencing the user with a rebuild.
Many users have reported problems that stem from having an unclean
working tree. To that end, I've written a guix-clean script which should
help reset the working tree while respecting user-specified precious
directories.
Precious directories, such as:
- SOURCES_PATH
- BASE_CACHE
- SDK_PATH
- OUTDIR
Should be preserved when cleaning the working tree, and are thus
recorded in ./contrib/guix/var/precious_dirs.
The ./contrib/guix/guix-clean script is able to parse that file and make
sure to avoid them when cleaning out the working tree.
laanwj