Log tool output (#371)

src/python/replay_merge.py

@@ -1,7 +1,8 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 """Replay merges and their test results.
-The output appears in the .workdirs/ directory.
+The output appears in the `.workdirs`/ directory.
+Logs appear in the `replay_logs/merges/` directory.
 Command-line arguments are listed just after the line:
   if __name__ == "__main__":
 

src/python/repo.py

@@ -558,13 +558,18 @@ def merge(
             str(timeout),
             f"src/scripts/merge_tools/{tool.name}.sh {self.local_repo_path.resolve()} {LEFT_BRANCH_NAME} {RIGHT_BRANCH_NAME}",
         ]
+        logger.debug(
+            f"merge: Merging {self.repo_slug} {left_commit} {right_commit} with {tool.name}"
+        )
         p = subprocess.run(
             command,
             capture_output=True,
             check=False,
         )
+        std_streams = stdout_and_stderr(command, p)
+        logger.debug(std_streams)
         if p.returncode == 124:  # Timeout
-            explanation = explanation + "\n" + stdout_and_stderr(command, p)
+            explanation = explanation + "\n" + std_streams
             if use_cache:
                 cache_entry["merge status"] = MERGE_STATE.Merge_timedout.name
                 cache_entry["explanation"] = explanation
@@ -583,7 +588,7 @@ def merge(
                 -1,
             )
         run_time = time.time() - start_time
-        explanation = explanation + "\n" + stdout_and_stderr(command, p)
+        explanation = explanation + "\n" + std_streams
         merge_status = (
             MERGE_STATE.Merge_success if p.returncode == 0 else MERGE_STATE.Merge_failed
         )