synapse dumps core at startup, intermittent issue

[greg one]

archlinux,gnome 3.20, tried with built-in 'run on startup' and also tweak tools autostart (which puts synapse.desktop in .config/autostart), same issue, intermittent crashes when synapse tries to start, it happens significantly often (1/2 times in 4/5 system starts), core dump is like this:
Sep 28 20:58:52 laptop systemd-coredump[763]: Process 678 (synapse) of user 1000 dumped core.

                                              Stack trace of thread 750:
                                              #0 0x00007f1dac6e479b g_logv (libglib-2.0.so.0)
                                              #1 0x00007f1dac6e490f g_log (libglib-2.0.so.0)
                                              #2 0x00007f1dac9d61ed g_type_create_instance (libgobject-2.0.so.0)
                                              #3 0x00007f1dacfa8e86 zeitgeist_symbol_info_register (libzeitgeist-2.0.so.0)
                                              #4 0x00007f1dacfa91c0 zeitgeist_symbol_initialize_symbols (libzeitgeist-2.0.so.0)
                                              #5 0x00007f1dacfafab1 zeitgeist_symbol_get_all_children (libzeitgeist-2.0.so.0)
                                              #6 0x00007f1dacfb320a zeitgeist_db_reader_get_where_clause_for_symbol (libzeitgeist-2.0.
                                              #7 0x00007f1dacfb3df1 zeitgeist_db_reader_get_where_clause_from_event_templates (libzeit
                                              #8 0x00007f1dacfb4713 zeitgeist_db_reader_get_where_clause_for_query (libzeitgeist-2.0.s
                                              #9 0x00007f1dacfb4952 zeitgeist_db_reader_find_event_ids (libzeitgeist-2.0.so.0)
                                              #10 0x00007f1dacfb4b85 zeitgeist_db_reader_find_events (libzeitgeist-2.0.so.0)
                                              #11 0x00007f1dacf96316 n/a (libzeitgeist-2.0.so.0)
                                              #12 0x00007f1dacf979d3 n/a (libzeitgeist-2.0.so.0)
                                              #13 0x00007f1dac704d3e n/a (libglib-2.0.so.0)
                                              #14 0x00007f1dac704345 n/a (libglib-2.0.so.0)
                                              #15 0x00007f1dac47e454 start_thread (libpthread.so.0)
                                              #16 0x00007f1dac1c17df __clone (libc.so.6)

                                              Stack trace of thread 701:
                                              #0 0x00007f1dac1b848d poll (libc.so.6)
                                              #1 0x00007f1dac6de066 n/a (libglib-2.0.so.0)
                                              #2 0x00007f1dac6de17c g_main_context_iteration (libglib-2.0.so.0)
                                              #3 0x00007f1dac6de1c1 n/a (libglib-2.0.so.0)
                                              #4 0x00007f1dac704345 n/a (libglib-2.0.so.0)
                                              #5 0x00007f1dac47e454 start_thread (libpthread.so.0)
                                              #6 0x00007f1dac1c17df __clone (libc.so.6)

[getzze (getzze)]

Same problem with Arch and Gnome 3.20, even with all the zeitgeist-related plugins disabled.
This workaround was working most of the time:
https://bugs.launchpad.net/synapse-project/+bug/1401909
However, synapse would crash occasionally so now I use a systemd user service that restarts automatically. The service cannot be enabled because systemd isn't noticed when gnome is started. Instead a .desktop file starts the service:

> ~/.config/autostart/synapse-systemd.desktop

[Desktop Entry]
Name=Synapse
Exec=systemctl --user start synapse.service
Encoding=UTF-8
Type=Application
X-GNOME-Autostart-enabled=true
Icon=synapse

> ~/.config/systemd/user/synapse.service

[Unit]
Description=Synapse launcher

[Service]
ExecStart=/usr/bin/synapse -s
Restart=always
RestartSec=20

Don't forget to uncheck Startup on login in the GUI.