Reject --tracemalloc in pyperf command

TODO.rst

@@ -2,7 +2,6 @@ BUGS
 ====
 
 * Repair PyPy on Travis
-* Reject --tracemalloc in bench_command()
 * BUG: "python pyperf timeit --compare-to=pypy" doesn't tune correctly the runner
   for pypy. pypy requires more warmup values (10) than cpython (1).
 * BUG: --duplicate of timeit must be ignored in PyPy, see the discussion

pyperf/_command.py

@@ -47,6 +47,7 @@ def __init__(self, runner, name, command):
 
     def compute(self):
         WorkerTask.compute(self)
+        assert not self.args.tracemalloc
         if self.args.track_memory:
             value = self.metadata.pop('command_max_rss', None)
             if not value:

pyperf/_runner.py

@@ -305,10 +305,13 @@ def _process_args_impl(self):
             self._only_in_worker("--worker-task")
 
         if args.tracemalloc:
-            try:
-                import tracemalloc   # noqa
-            except ImportError as exc:
-                raise CLIError("fail to import tracemalloc: %s" % exc)
+            if args.action == 'command':
+                raise CLIError('--tracemalloc cannot be used with pyperf command')
+            else:
+                try:
+                    import tracemalloc   # noqa
+                except ImportError as exc:
+                    raise CLIError("fail to import tracemalloc: %s" % exc)
 
         if args.track_memory:
             if MS_WINDOWS: