Add more information to job process failure error (#7251)

src/System.Management.Automation/engine/remoting/fanin/OutOfProcTransportManager.cs

@@ -708,8 +708,32 @@ namespace System.Management.Automation.Remoting.Client
                 //
                 stdInWriter.StopWriting();
             }
-            PSRemotingTransportException psrte = new PSRemotingTransportException(PSRemotingErrorId.IPCServerProcessExited,
-                                RemotingErrorIdStrings.IPCServerProcessExited);
+
+            // Try to get details about why the process exited
+            // and if they're not available, give information as to why
+            string processDiagnosticMessage;
+            try
+            {
+                var jobProcess = (Process)sender;
+                processDiagnosticMessage = StringUtil.Format(
+                    RemotingErrorIdStrings.ProcessExitInfo,
+                    jobProcess.ExitCode,
+                    jobProcess.StandardOutput.ReadToEnd(),
+                    jobProcess.StandardError.ReadToEnd());
+            }
+            catch (Exception exception)
+            {
+                processDiagnosticMessage = StringUtil.Format(
+                    RemotingErrorIdStrings.ProcessInfoNotRecoverable,
+                    exception.Message);
+            }
+
+            string exitErrorMsg = StringUtil.Format(
+                RemotingErrorIdStrings.IPCServerProcessExited,
+                processDiagnosticMessage);
+            var psrte = new PSRemotingTransportException(
+                PSRemotingErrorId.IPCServerProcessExited,
+                exitErrorMsg);
             RaiseErrorHandler(new TransportErrorOccuredEventArgs(psrte, transportMethod));
         }
 

src/System.Management.Automation/resources/RemotingErrorIdStrings.resx

@@ -794,7 +794,7 @@ Do you want to continue?</value>
     <value>The background process reported an error with the following message: {0}.</value>
   </data>
   <data name="IPCServerProcessExited" xml:space="preserve">
-    <value>The background process closed or ended abnormally.</value>
+    <value>The background process closed or ended abnormally: {0}.</value>
   </data>
   <data name="IPCErrorProcessingServerData" xml:space="preserve">
     <value>There is an error processing data from the background process. Error reported: {0}.</value>
@@ -1657,4 +1657,14 @@ All WinRM sessions connected to PowerShell session configurations, such as Micro
   <data name="WSManClientDllNotAvailable" xml:space="preserve">
     <value>This parameter set requires WSMan, and no supported WSMan client library was found. WSMan is either not installed or unavailable for this system.</value>
   </data>
+  <data name="ProcessExitInfo" xml:space="preserve">
+    <value>
+      Exit code: {0}
+      Stdout: '{1}'
+      Stderr: '{2}'
+    </value>
+  </data>
+  <data name="ProcessInfoNotRecoverable" xml:space="preserve">
+    <value>Information about the process could not be read: '{0}'.</value>
+  </data>
 </root>