Do not compute checksums on macOS

gns3server/main.py

@@ -77,13 +77,11 @@ def main():
     Entry point for GNS3 server
     """
 
-    if hasattr(sys, "frozen"):
-        multiprocessing.freeze_support()
-        multiprocessing.set_start_method("spawn")
-
     if not sys.platform.startswith("win"):
         if "--daemon" in sys.argv:
             daemonize()
+    else:
+        multiprocessing.freeze_support()
 
     from gns3server.run import run
     run()

gns3server/web/web_server.py

@@ -29,7 +29,6 @@ import functools
 import time
 import atexit
 import weakref
-import concurrent.futures
 
 # Import encoding now, to avoid implicit import later.
 # Implicit import within threads may cause LookupError when standard library is in a ZIP
@@ -238,7 +237,11 @@ class WebServer:
         Compute image checksums.
         """
 
+        if sys.platform.startswith("darwin") and hasattr(sys, "frozen"):
+            # do not compute on macOS because errors
+            return
         loop = asyncio.get_event_loop()
+        import concurrent.futures
         with concurrent.futures.ProcessPoolExecutor(max_workers=1) as pool:
             try:
                 log.info("Computing image checksums...")