systemd: use SIGINT to stop lilac-worker

and there is no need to kill it when timed out now.

lilac2/systemd.py

@@ -42,6 +42,7 @@ def start_cmd(
     'systemd-run', '--pipe', '--quiet', '--user',
     '--wait', '--remain-after-exit', '-u', name,
     '-p', 'CPUWeight=100', '-p', 'KillMode=process',
+    '-p', 'KillSignal=INT',
   ]
 
   if cwd := kwargs.pop('cwd', None):
@@ -140,9 +141,6 @@ def poll_rusage(name: str, deadline: float) -> tuple[RUsage, bool]:
         nsec = int(v)
 
   finally:
-    if timedout:
-      logger.debug('killing worker service')
-      subprocess.run(['systemctl', '--user', 'kill', '--kill-whom=main', '--signal=SIGINT', name])
     logger.debug('stopping worker service')
     # stop whatever may be running (even from a previous batch)
     subprocess.run(['systemctl', '--user', 'stop', '--quiet', name])

lilac2/worker.py

@@ -241,6 +241,12 @@ def main() -> None:
       # mod failed to load
       info = load_lilacinfo(Path('.'))
       handle_failure(e, repo, info, Path(input['logfile']))
+  except KeyboardInterrupt:
+    logger.info('KeyboardInterrupt received')
+    r = {
+      'status': 'failed',
+      'msg': 'KeyboardInterrupt',
+    }
   finally:
     # say goodbye to all our children
     kill_child_processes()