Fix #3410 - UnauthorizedAccessException writing to MyProject.paket.references.cached

[yaakov-h]

Root cause as discussed in #3410 - a source control system that marks paket.references as read-only.

I mostly made the integration test by copying it from the one above. It fails without the changes from the second commit, and passes with them. 😃

I made two changes:

1. Before deleting obj\foo.csproj.paket.references.cached we clear the read-only flag, so that Paket can upgrade from a broken version without issue.
2. After copying obj\foo.csproj.paket.references.cached we clear the read-only flag, so that this doesn't re-occur, and so none of the intermediary obj files are read-only.

[forki]

Can you please take a look at the CI errors? Thx

[yaakov-h]

Hmmm. I can't reproduce the Windows failure, nor the Linux failure on Mono 4.6.

I'll try grab latest Mono (5.x) and see if I can figure anything out.

[yaakov-h]

The core issue seems to be a bug in Mono where File.GetAttributes(...)/FileSystemInfo.Attributes returns -1, so FileSystemInfo.set_IsReadOnly attempts to set the attributes to -1 | ReadOnly which is an invalid combination, and throws.

I haven't managed to cleanly reproduce, and it seems odd to be messing with read-only on Linux, since read-only is actually a Windows thing. On Linux and macOS, Mono and .NET Core emulate the read-only bit by adjusting the file write bits.

As such, I've locked the file-read-only behavior to Windows only, which is probably the only place where this sort of bug would be legitimately encountered anyway.

[forki]

It's still red on the appveyor.

[forki]

2. Error : Paket.IntegrationTests.RestoreSpec.Paket failed with UnauthorizedAccessException writing to MyProject.paket.references.cached #3410 Paket restore fails when obj files are readonly
   System.IO.DirectoryNotFoundException : Could not find a part of the path 'C:\projects\paket\integrationtests\scenarios\i003410-readonly-obj\temp\dotnet\obj\dotnet.csproj.paket.references.cached'.

[yaakov-h]

Yeah, looking into it now.

Do you have any idea why another test is also failing with a readonly file error?

I'm not familiar with the internal test infrastructure or if there are dependencies between tests / dirty state / etc.

[forki]

the other one may be unrelated

[yaakov-h]

integrationtests/scenarios/*/before/**/obj is in .gitignore, so one of my test input files was never present. 😭

🤞 it'll be good now

[yaakov-h]

@forki any idea what's with integration test i003012? I haven't touched it, and my new test isn't leaving anything behind...

[forki]

It says:

UnauthorizedAccessException: Access to the path 'C:\projects\paket\integrationtests\scenarios\i003012\temp\dotnet\obj\dotnet.csproj.paket.references.cached' is denied.

[yaakov-h]

I can see that, but I cannot for the life of me figure out why.

Are tests run in parallel, perhaps?

[yaakov-h]

I can't even reproduce it locally anymore. 😢

[qiuhaotc]

Same problem and that project is also .net core project😫

[yaakov-h]

@forki fixed appveyor 😄

[forki]

thanks!!!