new test failure on s390x (big-endian / IBM System Z) in image v0.24.8 compared to v0.24.7

[decathorpe]

I'm responsible for building the packages for the image crate for Fedora Linux, and I noticed a test failure that is new in image v0.24.8.

The failing test is check_references from the tests/reference_images.rs file:

failures:
---- check_references stdout ----
check_references tests/reference/tga/testsuite/cbw8.tga.3f8a9b3c.png
check_references tests/reference/tga/testsuite/ctc24.tga.b7096b3.png
check_references tests/reference/tga/testsuite/ubw8.tga.3f8a9b3c.png
check_references tests/reference/tga/testsuite/utc24.tga.b7096b3.png
check_references tests/reference/tga/testsuite/utc32.tga.134a83ba.png
check_references tests/reference/tiff/testsuite/hpredict.tiff.dc00a927.png
check_references tests/reference/tiff/testsuite/hpredict_packbits.tiff.82ca6aa0.png
check_references tests/reference/tiff/testsuite/mandrill.tiff.99549da9.png
check_references tests/reference/tiff/testsuite/rgb-3c-16b.tiff.531c087a.png
thread 'check_references' panicked at tests/reference_images.rs:278:13:
The decoded image's hash does not match (expected = 531c087a, actual = a7d24c79).
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failures:
    check_references

s390x is the only big-endian architecture we support, so I suspect this as a likely cause of the issue. This test passes on all other architectures we support (x86_64, i686, aarch64, powerpc64le).

The parse_crc function in the same file looks suspiciously like it would not work as expected on architectures with big-endian byte order ... but its code has not changed since v0.24.7, so I'm not sure if this is the cause.

Test environment:

• Fedora Rawhide
• Rust 1.75.0
• on s390x-unknown-linux-gnu

[fintelia]

Thanks for reporting this! We're supposed to have CI validating that our tests pass on a big endian system. Unfortunately, it seems the overall CI runs have been showing as green despite the specific big endian checks not actually passing...

[decathorpe]

Thank you for the quick fix!