cmWorkerPool: Show process exit code / signal number upon failure

Previously if an AUTOGEN process like moc exited with a non-zero exit
code, cmWorkerPool would not populate the result's ErrorMessage
because it mistakenly thought that if the ExitCode / TermSignal had a
non-zero value, the ErrorMessage must have already been set.

This was a wrong assumption.

Instead, check if ErrorMessage is empty, and if it is, set it to
whatever the exit code or term signal number is.

1 files changed, 1 insertions, 1 deletions

diff --git a/Source/cmWorkerPool.cxx b/Source/cmWorkerPool.cxx
index 1d15c27..27cdbba 100644
--- a/Source/cmWorkerPool.cxx
+++ b/Source/cmWorkerPool.cxx
@@ -309,7 +309,7 @@ void cmUVReadOnlyProcess::UVExit(uv_process_t* handle, int64_t exitStatus,
     // Set error message on demand
     proc.Result()->ExitStatus = exitStatus;
     proc.Result()->TermSignal = termSignal;
-    if (!proc.Result()->error()) {
+    if (proc.Result()->ErrorMessage.empty()) {
       if (termSignal != 0) {
         proc.Result()->ErrorMessage = cmStrCat(
           "Process was terminated by signal ", proc.Result()->TermSignal);