orchestration/exectools.py: fix getting stuck on terminating components

The reason we didn't spot this earlier is that exceptions were swallowed
by the call to `asyncio.wait()` in
`runners.py:ExperimentBaseRunner.terminate_collect_sims()` when invoking
`int_term_kill()`. Instead, we now use `asyncio.gather()`, which
forwards exceptions to the calling coroutine.

experiments/simbricks/orchestration/exectools.py

@@ -148,7 +148,8 @@ class Component(object):
         try:
             await asyncio.wait_for(self._proc.wait(), delay)
             return
-        except TimeoutError:
+        # before Python 3.11, asyncio.wait_for() throws asyncio.TimeoutError -_-
+        except (TimeoutError, asyncio.TimeoutError):
             print(
                 f'terminating component {self.cmd_parts[0]} '
                 f'pid {self._proc.pid}',
@@ -159,14 +160,13 @@ class Component(object):
         try:
             await asyncio.wait_for(self._proc.wait(), delay)
             return
-        except TimeoutError:
+        except (TimeoutError, asyncio.TimeoutError):
             print(
                 f'killing component {self.cmd_parts[0]} '
                 f'pid {self._proc.pid}',
                 flush=True
             )
             await self.kill()
-
         await self._proc.wait()
 
     async def started(self) -> None:

experiments/simbricks/orchestration/runners.py

@@ -162,24 +162,24 @@ class ExperimentBaseRunner(ABC):
         scs = []
         for _, sc in self.running:
             scs.append(asyncio.create_task(sc.int_term_kill()))
-        await asyncio.shield(asyncio.wait(scs))
+        await asyncio.gather(*scs)
 
         # wait for all processes to terminate
         for _, sc in self.running:
-            await asyncio.shield(sc.wait())
+            await sc.wait()
 
         # remove all sockets
         scs = []
         for (executor, sock) in self.sockets:
             scs.append(asyncio.create_task(executor.rmtree(sock)))
         if scs:
-            await asyncio.shield(asyncio.wait(scs))
+            await asyncio.wait(scs)
 
         # add all simulator components to the output
         for sim, sc in self.running:
             self.out.add_sim(sim, sc)
 
-        await asyncio.shield(self.after_cleanup())
+        await self.after_cleanup()
         return self.out
 
     async def run(self) -> ExpOutput:
@@ -222,7 +222,8 @@ class ExperimentBaseRunner(ABC):
         while True:
             try:
                 return await asyncio.shield(terminate_collect_task)
-            except asyncio.CancelledError:
+            except asyncio.CancelledError as e:
+                print(e)
                 pass