Vips::SourceCustom test failure in Debian

[lucaskanashiro]

Describe the bug
When running tests of version 2.1.4 in Debian we get the following failure:

  1) Vips::SourceCustom can write an image to a user output stream
     Failure/Error: expect(image.avg).to be_within(0.001).of(109.789)
       expected 109.41407425505706 to be within 0.001 of 109.789

This happens all the time, which makes me think if the range (0.001) is indeed correct.

To Reproduce
Steps to reproduce the behavior:

1. Grab the debian package for ruby-vips version 2.1.4 (latest version)
2. Try to build it.

I believe if you simple try to run tests in Debian unstable you will get the same failure. Currently the default is ruby 3.1.

Expected behavior
All tests pass.

Desktop (please complete the following information):

• OS: Debian
• Version: unstable (sid)

[jcupitt]

Hi @lucaskanashiro, you're right, it fails on current Ubuntu as well, I wonder what changed.

I'll have a look, thanks for the report.

[jcupitt]

Oooof, it's actually a libvips bug, I've fixed it in 8.13 and in master, so ruby-vips now passes when built against the latest libvips.

ruby-vips will need a workaround when testing with libvips 8.13. I'll try to find one that's not too ugly.

[jcupitt]

Ugh, not very pretty but git master ruby-vips has a workaround. Would you be able to test? Any suggestions for a less ugly test would be very welcome too.