Improve always-on-trace

Notes to the user need to go to stderr, and tracing should not be on for
fast exiting invocations (such as --help).

This makes it so that release/update-manpages works.

Change-Id: Ib183193c868a78c295a184c01c4532cd53d512eb
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/350794
Tested-by: LaMont Jones <lamontjones@google.com>
Reviewed-by: Xin Li <delphij@google.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/repo_trace.py b/repo_trace.py
index 0ff3b694..03542950 100644
--- a/repo_trace.py
+++ b/repo_trace.py
@@ -119,7 +119,7 @@ def _GetTraceFile():
   # TODO: refactor to pass repodir to Trace.
   repo_dir = os.path.dirname(os.path.dirname(__file__))
   trace_file = os.path.join(repo_dir, _TRACE_FILE_NAME)
-  print('Trace outputs in %s' % trace_file)
+  print('Trace outputs in %s' % trace_file, file=sys.stderr)
   return trace_file
 
 def _ClearOldTraces():