Add tests for handling missing and non-executable test.sh in build process.

[rohitpaulk]

Note

Validate presence/executability of tester test.sh, add tests for failures, broaden Dockerfile distro handling, and bump language fixtures.

• Builder (Go):
  • Validate tester_dir/test.sh exists and is executable before building; return internal errors if missing/invalid.
• Tests:
  • Add cases for missing and non-executable test.sh with assertions on error logs.
  • Allow injecting tester_dir into BuildImageCommandRunner#run.
• Dockerfile processing:
  • Broaden detection to include debian, noble, trixie; clarify error message for unknown FROM lines.
• Fixtures/Makefile:
  • Update Redis repo commit and switch fixtures to ruby-3.4, rust-1.91, go-1.25; adjust CodeFixtures and copy paths accordingly.

^{Written by Cursor Bugbot for commit 1f3adae. This will update automatically on new commits. Configure here.}

[cursor]

Bug: Bare rescue catches flunk exception masking test failures

The bare rescue catches all StandardError subclasses, including Minitest::Assertion raised by flunk. If run_script! unexpectedly succeeds, flunk is called but immediately caught by the rescue block, causing the test to continue rather than fail with the intended message. The test would eventually fail at subsequent assertions but with a confusing error message, making debugging harder. The rescue block needs to specify the expected exception type (like RuntimeError) to avoid swallowing the flunk assertion.

Additional Locations (1)

• builder/tests/build_image_test.rb#L190-L196