cabal-testsuite failures on Windows due to the max path length

[phadej]

I trying disable few tests on windows & appveyor, they weren't run previously anyway.

• cabal-testsuite\PackageTests\Regression\T5309\cabal.test.hs
• cabal-testsuite\PackageTests\Regression\T5677\cabal.test.hs
• cabal-testsuite\PackageTests\Backpack\Includes3\cabal-internal.test.hs
• cabal-testsuite\PackageTests\Backpack\Includes3\cabal-external.test.hs
• cabal-testsuite\PackageTests\Backpack\Includes2\cabal-internal.test.hs
• cabal-testsuite\PackageTests\Backpack\Includes2\cabal-external.test.hs
• cabal-testsuite\PackageTests\Backpack\bkpcabal01\cabal.test.hs

[phadej]

@Mistuke

Does

C:\WORK\cabal-testsuite\PackageTests\Backpack\Includes3\cabal-internal.dist\work\.\dist\build\x86_64-windows\ghc-8.6.5\Includes3-0.1.0.0\l\indef\Includes3-0.1.0.0-inplace-indef+AZNSCvlbjiwGW3rUT5hCYh\build\Includes3-0.1.0.0-inplace-indef+AZNSCvlbjiwGW3rUT5hCYh\autogen\: openBinaryTempFileWithDefaultPermissions:

Look like path length limitation? Is there anything one can do to make it not fail?

[Mistuke]

Yeah that path is way too long. Which ghc and Cabal is this?

[Mistuke]

You can try this before the build/testsuite raaz-crypto/raaz@78a8459

For newer cabal and ghc you can install ghc-jailbreak which would take care of it too.

[phadej]

@Mistuke, Cabal is master. In cabal-testsuite, we indeed have quite long CWD to begin with. Making X: is a nice trick, have to try that.

But the GHC used, is 8.6.5, will ghc-jailbreak work with it, or does one need 8.8?

[phadej]

I'd try ghc-jailbreak if it works, before making X: trick. I recall you blogged about it, but I cannot find that anymore, do you have a link?

[Mistuke]

It depends. I'm not quite sure who is issuing this error.. If it's coming from cabal or ghc. openBinaryTempFileWithDefaultPermissions sounds like it's coming from base openBinaryTempFileWithDefaultPermissions in which case only the X: trick will work until ghc 8.12 because the temp file function in base doesn't use the MAX_PATH workaround and ghc-jailbreak only patches the tools ghc depends on and not ghc itself.

Blog post is at https://hub.zhox.com/posts/bypassing-max_path-limit-on-windows/ but I think it won't work in this case.