On 8/5/2026 11:58 PM, Mathieu Dubois-Briand via lists.openembedded.org wrote:
On Wed Aug 5, 2026 at 12:04 AM CEST, Alejandro Hernandez Samaniego via lists.openembedded.org wrote:
RUST_BUILD_SYS is currently listed in BB_BASEHASH_IGNORE_VARS, which
tells bitbake that rust recipes should hash-match regardless of the
build machine's triplet. In practice that is not true:

rustc computes each crate's Strict Version Hash (SVH) using inputs
that include the *stage0/stage1 bootstrap compiler* fingerprint, which
in turn depends on the build host arch. That seed cascades through
every dependent crate's mangled symbols and the packing order of
rodata sections, so an sstate blob populated on one worker arch and
reused on a differently-arched worker produces byte-different (but
semantically identical) artifacts and fails the reproducibility
selftest causing autobuilder intermittent issues when the sstate
matches for the incorrect architecture.

Remove RUST_BUILD_SYS from BB_BASEHASH_IGNORE_VARS so the task hash
tracks the build triplet and mixed-arch autobuilder pools get an
sstate miss instead of a silently-wrong hit. RUST_HOST_SYS and
RUST_TARGET_SYS stay excluded because they're already covered by the
target/host arch hash inputs.

While this is not ideal, it should unblock the reproducible test case,
another solution would be to patch rust sources manually and attempt
to upstream that change.

This also has the side-effect that multiple variants of the conflicting
rust recipes sstate artifacts are created, but they'll be correctly used
now in each architecture.

Also add an explanatory comment next to the RUST_*_SYS[vardepvalue]
declarations in rust-common.bbclass so future readers don't re-add
the exclusion.

Verified locally: Tier 1 sighash test toggling BUILD_ARCH now produces
different task hashes for rust/libstd-rs/rpm-sequoia/python3-crypto-
graphy/cargo/librsvg, where previously the hashes matched despite the
build machine change.

[YOCTO #15554]

Assisted-by: AI - OpenAI
Signed-off-by: Alejandro Hernandez <alhe@linux.microsoft.com>
---
Hi Alejandro,

It looks like this is breaking some selftests:

2026-08-05 10:11:05,494 - oe-selftest - INFO - sstatetests.SStateHashSameSigs.test_sstate_sdk_arch_same_hash (subunit.RemotedTestCase)
2026-08-05 10:11:05,494 - oe-selftest - INFO -  ... FAIL
...

2026-08-05 10:11:05,495 - oe-selftest - INFO - 6: 27/69 496/763 (108.24s) (2 failed) (sstatetests.SStateHashSameSigs.test_sstate_sdk_arch_same_hash)
2026-08-05 10:11:05,495 - oe-selftest - INFO - testtools.testresult.real._StringException: Traceback (most recent call last):
  File "/srv/pokybuild/yocto-worker/oe-selftest-debian/build/layers/openembedded-core/meta/lib/oeqa/selftest/cases/sstatetests.py", line 416, in test_sstate_sdk_arch_same_hash
    self.sstate_hashtest("aarch64")
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File "/srv/pokybuild/yocto-worker/oe-selftest-debian/build/layers/openembedded-core/meta/lib/oeqa/core/decorator/__init__.py", line 35, in wrapped_f
    return func(*args, **kwargs)
  File "/srv/pokybuild/yocto-worker/oe-selftest-debian/build/layers/openembedded-core/meta/lib/oeqa/selftest/cases/sstatetests.py", line 401, in sstate_hashtest
    self.assertCountEqual(files1, files2)
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/unittest/case.py", line 1238, in assertCountEqual
    self.fail(msg)
    ~~~~~~~~~^^^^^
  File "/usr/lib/python3.13/unittest/case.py", line 732, in fail
    raise self.failureException(msg)
AssertionError: Element counts were not equal:
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/gtk+3-native/3.24.52.do_create_spdx.sigdata.469683d7e676bd4feadb3e363efaa9a55c47eb06559fcda0d3f5cf26473919c5'
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/gtk+3-native/3.24.52.do_populate_sysroot.sigdata.c29ff418823da4b52189a4cf7395c310a3c14fed57eb24562cd0e387fe2235a3'
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/gtk+3-native/3.24.52.do_create_package_spdx.sigdata.ede62d86abb84a871e239607d0a7173c6a9c45027aafffc624b37e2e1bb5111f'
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/rust-native/1.96.1.do_create_spdx.sigdata.76ed6652ba8e8eba4e8750240fa7a048fcc90e94b45e753068a44560ef2e29f0'
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/rust-native/1.96.1.do_create_package_spdx.sigdata.4234a33aff5f4b52703a74c1caec1893206476f908c70b32c78e46dcc3e4fb38'
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/rust-native/1.96.1.do_compile.sigdata.67ed98cf74ac06f829d6432f4fd904779b2f6e540f588baeab3dcf0ac35a9c75'
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/rust-native/1.96.1.do_populate_sysroot.sigdata.3203f6ea1fd6bb92ed523ba0e1ef0464166f1e5392207ea002c35e0007d435f9'
First has 1, Second has 0:  '/srv/pokybuild/yocto-worker/oe-selftest-debian/build/build-st-3278758/tmp-sstatesamehash/stamps/x86_64-linux/rust-native/1.96.1.do_configure.sigdata.df7cc5717b4cbc2ccb19bdb823fb55193cc2f95049ac7e07d440bc2da5590c96'
...

And same for sstatetests.SStateHashSameSigs.test_sstate_32_64_same_hash:
2026-08-05 10:07:29,974 - oe-selftest - INFO - sstatetests.SStateHashSameSigs.test_sstate_32_64_same_hash (subunit.RemotedTestCase)
2026-08-05 10:07:29,975 - oe-selftest - INFO -  ... FAIL
...

https://autobuilder.yoctoproject.org/valkyrie/#/builders/35/builds/4472
https://autobuilder.yoctoproject.org/valkyrie/#/builders/48/builds/4290

Can you have a look at the issue?

Thanks,
Mathieu
Thanks Mathieu, yes this actually make sense, this is why I wasn't too convinced since the beginning and wanted to send an RFC, I'll attempt to fix this in some other way.

Alejandro


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