MSBuildLocator fails in macOS GUI apps due to missing /usr/local/share/dotnet in PATH

[MattParkerDev]

On macOS, GUI applications launched via launchd (such as apps opened from Finder or the Dock) do not inherit the shell's PATH environment variable. As a result, the directory /usr/local/share/dotnet is typically missing from the PATH, causing MSBuildLocator to fail to find .NET installations.

System.InvalidOperationException: Path to dotnet executable is not set. The probed variables are: DOTNET_ROOT, DOTNET_HOST_PATH, DOTNET_MSBUILD_SDK_RESOLVER_CLI_DIR and PATH. Make sure, that at least one of the listed variables points to the existing dotnet executable.
   at Microsoft.Build.Locator.DotNetSdkLocationHelper.ResolveDotnetPathCandidates()
   at Microsoft.Build.Locator.DotNetSdkLocationHelper.<>c.<.cctor>b__17_0()
   at System.Lazy`1.ViaFactory(LazyThreadSafetyMode mode)
   at System.Lazy`1.ExecutionAndPublication(LazyHelper executionAndPublication, Boolean useDefaultConstructor)
   at System.Lazy`1.CreateValue()
   at Microsoft.Build.Locator.DotNetSdkLocationHelper.<GetInstances>g__GetSdkFromGlobalSettings|5_2(String workingDirectory)
   at Microsoft.Build.Locator.DotNetSdkLocationHelper.GetInstances(String workingDirectory, Boolean allowQueryAllRuntimes, Boolean allowAllDotnetLocations)+MoveNext()

My current workaround:

private static void FixMacosPath()
    {
        var processStartInfo = new ProcessStartInfo
        {
            FileName = "/bin/zsh",
            ArgumentList = { "-l", "-c", "printenv PATH" },
            RedirectStandardOutput = true,
            RedirectStandardError =  true,
            UseShellExecute = false,
        };
        using var process = Process.Start(processStartInfo);
        var output = process!.StandardOutput.ReadToEnd().Trim();
        process.WaitForExit();
        Environment.SetEnvironmentVariable("PATH", output, EnvironmentVariableTarget.Process);
    }

Ideally the shell PATH, or another relevant environment variable would be set for GUI apps.

[teo-tsirpanis]

We might need to search in /etc/dotnet/install_location if it exists as well.