Fixup use of multiprocessing.

lib/python/qmk/util.py

@@ -5,7 +5,6 @@
 import multiprocessing
 
 from milc import cli
-from milc.subcommand import config
 
 
 @contextlib.contextmanager
@@ -23,13 +22,6 @@ def parallelize():
     else:
         parallel_search = cli.config.user.parallel_search
 
-    # If we haven't already written a value, write it to the file
-    if cli.config.user.parallel_search != parallel_search:
-        cli.args.read_only = False
-        config.set_config('user', 'parallel_search', parallel_search)
-        cli.save_config()
-        cli.config.user.parallel_search = parallel_search
-
     # Non-parallel searches use `map()`
     if not parallel_search:
         yield map
@@ -51,4 +43,8 @@ def parallel_map(*args, **kwargs):
     """Effectively runs `map()` but executes it in parallel if necessary.
     """
     with parallelize() as map_fn:
-        return map_fn(*args, **kwargs)
+        # This needs to be enclosed in a `list()` as some implementations return
+        # a generator function, which means the scope of the pool is closed off
+        # before the results are returned. Returning a list ensures results are
+        # materialised before any worker pool is shut down.
+        return list(map_fn(*args, **kwargs))