Assertion due to periodic event initialization being too late.
Reported by Lunar in #tor-dev:
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(log_backtrace+0x41) [0x5644546256b1] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(tor_assertion_failed_+0x8d) [0x5644546338bd] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(reschedule_directory_downloads+0x6f) [0x5644545344df] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(learned_bridge_descriptor+0x394) [0x56445461b704] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(routerlist_descriptors_added+0xc3) [0x56445457a4a3] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(router_load_routers_from_string+0x429) [0x56445457db19] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(+0x88089) [0x56445457e089] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(router_reload_router_list+0x26) [0x56445457e0e6] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(do_main_loop+0x118) [0x564454534968] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(tor_main+0x19ad) [0x56445453812d] (on Tor 0.2.8.0-alpha-dev ) Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(main+0x19) [0x564454530889] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5) [0x7f9289bd9b45] (on Tor 0.2.8.0-alpha-dev )
Nov 18 12:03:38.000 [err] Bug: /usr/bin/tor(+0x3a8d9) [0x5644545308d9] (on Tor 0.2.8.0-alpha-dev )