Explicity set installation path - #498

Hi @jasoncouture,
Thanks for this, and apologies for the long silence.

We've opened #785, which fixes the same permission failure differently. The difference is where .NET goes instead.

Here, getInstallDirectory() returns RUNNER_TOOL_CACHE/dotnet before the platform default. Since RUNNER_TOOL_CACHE is always set on hosted runners, that path always wins there, so the .NET preinstalled under /usr/share/dotnet would stop being used and get downloaded again on every run. As noted on #518, we'd rather not change the install location for everyone to fix a case that affects self-hosted and ARC runners.

#785 keeps the default at priority 2 and falls back to $HOME/.dotnet only when the default isn't writable, so behaviour is unchanged wherever it already works. It also helps self-hosted runners that don't set RUNNER_TOOL_CACHE.

Happy to reconsider if there's something we've missed.

#785 has now been merged, which addresses the same permission failure by falling back to $HOME/.dotnet when the default location isn't writable. Since that covers the underlying problem without changing the install location for runners where it already works, I'm closing this one as superseded.

Thanks for raising it and for the patience on the long review time. The original report in #360 is now resolved as a result of your pushing on this.