Process.Start() failure should include path

[danmoseley]

When a process cannot be started, it would be useful for the exception to include the ProcessStartInfo or equivalent.

For example, I got this in the VS output window - I assume it's missing a certain dotnet.exe but I don't know which. I've encountered this in other situations.

Microsoft.VisualStudio.TestPlatform.ObjectModel.TestPlatformException: Failed to launch testhost with error: System.AggregateException: One or more errors occurred. ---> System.ComponentModel.Win32Exception: The system cannot find the file specified
   at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo)
   at System.Diagnostics.Process.Start()
   at Microsoft.VisualStudio.TestPlatform.PlatformAbstractions.ProcessHelper.LaunchProcess(String processPath, String arguments, String workingDirectory, IDictionary`2 envVariables, Action`2 errorCallback, Action`1 exitCallBack, Action`2 outputCallBack)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.LaunchHost(TestProcessStartInfo testHostStartInfo, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.<>c__DisplayClass38_0.<LaunchTestHostAsync>b__0()
   at System.Threading.Tasks.Task`1.InnerInvoke()

We already special case two codes
https://github.com/danmosemsft/runtime/blob/58e6ab1054b8809b3c91fcd75d1dbfff559e9573/src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Windows.cs#L612-L616

We would special case ERROR_DIRECTORY, ERROR_FILE_NOT_FOUND, ERROR_INVALID_PARAMETER, ERROR_INVALID_NAME, ERROR_PATH_NOT_FOUND, and ERROR_ACCESS_DENIED and for those include psi.FileName and psi.WorkingDirectory in the message. (Or just do it in all cases) and analogous in Unix:

runtime/src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Unix.cs

Line 528 in 1923bba

throw new Win32Exception(errno);

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[danmoseley]

Likely something like

@@ -613,7 +613,9 @@ private unsafe bool StartWithCreateProcess(ProcessStartInfo startInfo)
                         {
                             throw new Win32Exception(errorCode, SR.InvalidApplication);
                         }
-                        throw new Win32Exception(errorCode);
+
+                        string msg = SR.Format(SR.FailedToStartFileDirectory, startInfo.FileName, startInfo.WorkingDirectory, new Win32Exception(errorCode).Message);
+                        throw new Win32Exception(errorCode, msg);

and

+  <data name="FailedToStartFileDirectory" xml:space="preserve">
+    <value>Failed to start '{0}' with working directory '{1}'. {2}</value>
+  </data>

[danmoseley]

dotnet/msbuild#5355 is another example where this would be useful.

[danmoseley]

@Symbai @batzen both of you thumbsed up - any interest in taking this one?

[batzen]

Sure. Will use some of the time i reserved for Hacktobest and try to implement this.