Can anyone help me diagnose a strange issue on Windows CI?

[jgm]

Recently the Windows CI has started to fail in a very strange way. The build looks fine, but all the command tests are failing; each is failing with an exit code -1073741515.
See https://github.com/jgm/pandoc/actions/runs/8639531935/job/23686006131#step:6:1723

There's no other indication of why they are failing. Any ideas? Has something changed recently in the Windows CI setup on GitHub? It doesn't seem related to any change in the code, because I'm seeing the same error with a PR that doesn't incorporate today's changes, AND with today's changes in master.

[tarleb]

The only relevant info I could find online was this:

File system error -1073741515, also known as error 0xC0000135, is associated with registry issues and missing DLL files.

Apparently nothing that can be fixed on our end.

[tarleb]

And, FWIW, people on Microsoft projects seem to have similar issues.

[jgm]

I added an error in the test-windows-ci branch to see what path to the test executable was being passed into the command tests. It is

"D:\\a\\pandoc\\pandoc\\dist-newstyle\\build\\x86_64-windows\\ghc-9.4.4\\pandoc-3.1.13\\t\\test-pandoc\\noopt\\build\\test-pandoc\\test-pandoc.exe"

That looks okay.

[jgm]

I added something to the CI that just runs this program explicitly with the --emulate option (which is how we do command tests). It seemed to work fine.

[jgm]

To be clear, this diagnostic just deepens the mystery. Command tests still don't work, but evidently not because running the test program with --emulate doesn't work.

[jgm]

https://github.com/actions/runner-images/commits/main/
I don't see any changes in the windows-2019 image that lookrelevant in the last week.

[jgm]

Also tried expiring the cache, but that didn't help.

[jgm]

I've fixed this now. Your "and missing DLL files" was the clue I needed. We run command tests in a restricted path, and (I don't know why) something seems to have changed on the Windows build so that a DLL is required which is not found at that path. Appending the existing PATH to the path used for the command tests fixed the issue.