[incubator-ponymail-foal] branch master updated: migrate.py does not work on macos

[se...@apache.org]

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sebb pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-ponymail-foal.git


The following commit(s) were added to refs/heads/master by this push:
     new 78bc803  migrate.py does not work on macos
78bc803 is described below

commit 78bc803a6b231c6d0752334142ec4e257dd35517
Author: Sebb <se...@apache.org>
AuthorDate: Mon Dec 20 13:25:10 2021 +0000

    migrate.py does not work on macos
    
    This adds work-round for #158
---
 tools/migrate.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/migrate.py b/tools/migrate.py
index a981cc3..f7bd128 100644
--- a/tools/migrate.py
+++ b/tools/migrate.py
@@ -350,6 +350,17 @@ if __name__ == "__main__":
         help="Fail gracefully and continue if a processing error occurs",
         action='store_true'
     )
+    # the default on macOS is spawn, but this fails with:
+    #  ForkingPickler(file, protocol).dump(obj)
+    # TypeError: cannot pickle 'weakref' object
+    # Work-round: allow override of start method
+    parser.add_argument(
+        "--start_method",
+        help="Override start method (e.g. fork on macos)",
+        type=str
+    )
     args = parser.parse_args()
+    if args.start_method:
+        multiprocessing.set_start_method(args.start_method)
     loop = asyncio.get_event_loop()
     loop.run_until_complete(main(args.jobs, args.graceful))