chown local socket fails

I agree on the bug, but not the solution. It turns out that libmilter will handle this itself based on umask:

https://www.mirbsd.org/htman/i386/manDOCS/milter/smfi_setconn.html

The default uMask setting should yield an appropriately owned socket. I think we can just drop own_socketfile(milterconfig) completely. The reason why your patch appears to work is that the permissions have already been set by the time own_socketfile(milterconfig) is run. Since the milter has already dropped privileges at that point, if the socket was still root owned, it would fail.

Thanks for the feedback. There's already a pending update in Debian (to 1.0.2) that doesn't address this issue, so don't be surprised when you get an update and this isn't fixed.

If you can try removing (or commenting out) the own_socket line without re-adding it and verify that works on 1.0, I'll see about getting another update into Debian 10 (Buster).

Yes, it helps. Service started without issues, using local socket.

Fix committed to master for version 1.2.0. Will cherry-pick for 1.1 and 1.0 stable branches.

Committed for stable1.0 and stable1.1 also.

1.1.4 2019-11-22
 - Make error logging more explicit to aid debugging
 - Delete own_socketfile to resolve race condition where the permissions
   change fails on a Unix socket because it hasn't been created yet (libmilter
   will do this correctly on its own based on umask, the milter doesn't need
   to do it) (LP: #1849712)

I've also released 1.0.3 with this fix in it for python2 users. For Debian users, once 1.1.4 is in Testing, I plan to ask the release team for authorization to do a stable update with 1.0.3. Assuming that is approved, it would be in the next point release.