Change NuGet cache to be in repository root

[Youssef1313]

Related to #7187.

[Youssef1313]

@elachlan This seems to work for CI. But I'm not sure if it will work well for local development. Haven't cloned the repository so I can't test.

Can we use something like https://stackoverflow.com/a/20014410/5108631? But we definitely want to revert the environment variable back to its original state after build.

Note that we can simply delete the environment variable, which will then have the effect from NuGet.config

[elachlan]

Should this be dotnet_diagnostic.severity = suggestion?

[Youssef1313]

I'm disabling CA2208 specifically so that you can clearly see what rules are violated by the referenced packages.

[elachlan]

@Youssef1313 This doesn't work locally. I still get the standard errors. Thanks for your efforts though.

C:\Users\elachan\.nuget\packages\microsoft.codeanalysis.collections\4.0.0-4.21379.20\contentFiles\cs\nets
tandard2.0\ImmutableSegmentedList`1.cs(346,23): error CA2208: Call the ArgumentException constructor that contains a me
ssage and/or paramName parameter [D:\Development\msbuild\src\Framework\Microsoft.Build.Framework.csproj]

@Forgind I think this solution might work if we can fix that quirk with local build. Otherwise we can just move back to using editorconfigs.

Edit: the error is pointing to my user directory, not the cache you configured.

[Youssef1313]

@elachlan Do you have NUGET_PACKAGES environment variable set to anything? The NUGET_PACKAGES has precedence over the path defined in NuGet.config

[elachlan]

@elachlan Do you have NUGET_PACKAGES environment variable set to anything?

I just run "build" from the msbuild root via cmd prompt. As far as I can tell that env variable is not set.

[Youssef1313]

@elachlan Do you have NUGET_PACKAGES environment variable set to anything?

I just run "build" from the msbuild root via cmd prompt. As far as I can tell that env variable is not set.

The environment variable is the only thing that can take precedence over NuGet.config. I think arcade has set it for your local environment?

msbuild/eng/common/tools.ps1

Line 49 in 90275e4

[bool]$useGlobalNuGetCache = if (Test-Path variable:useGlobalNuGetCache) { $useGlobalNuGetCache } else { !$ci }

Here, useGlobalNuGetCache is likely set to !ci which is true for your local environment. Then:

msbuild/eng/common/tools.ps1

Lines 608 to 623 in 90275e4

	function GetNuGetPackageCachePath() {
	if ($env:NUGET_PACKAGES -eq $null) {
	# Use local cache on CI to ensure deterministic build.
	# Avoid using the http cache as workaround for https://github.com/NuGet/Home/issues/3116
	# use global cache in dev builds to avoid cost of downloading packages.
	# For directory normalization, see also: https://github.com/NuGet/Home/issues/7968
	if ($useGlobalNuGetCache) {
	$env:NUGET_PACKAGES = Join-Path $env:UserProfile '.nuget\packages\'
	} else {
	$env:NUGET_PACKAGES = Join-Path $RepoRoot '.packages\'
	$env:RESTORENOCACHE = $true
	}
	}
	return $env:NUGET_PACKAGES
	}

[Youssef1313]

I think we can just pass false for useGlobalNuGetCache from the build script and things should work smoothly?

[elachlan]

We need to check with the team to confirm this is a good idea. They might dislike the idea of not using the global cache.

It might be simpler to just use the editorconfig in conjunction with the globalconfig as outlined in dotnet/roslyn#55992

[Youssef1313]

Sure. I'm going to close for now. You can incorporate either using editorconfigs and globalconfigs, or using the local nuget cache approach in #7187 as you and the team see what's more suitable.

[elachlan]

Sure. I'm going to close for now. You can incorporate either using editorconfigs and globalconfigs, or using the local nuget cache approach in #7187 as you and the team see what's more suitable.

Thank you so much for your help on this. It gives us a good idea on what is possible.