crash: Assertion node->rs->is_possible_guard failed in compute_weighted_bandwidths at

With https://github.com/toralf/torutils/blob/f307866d2149bcd3c95df5269b3b48d051f871e9/info.py I monitor the status of my 2 Tor relays. A day before I commented out this section in torrc:

#FetchDirInfoEarly 1
#FetchDirInfoExtraEarly 1
#FetchUselessDescriptors 1
#UseMicrodescriptors 0
#DownloadExtraInfo 1

Now it took 7 minutes to finish (when those config values were set it was much faster).

But more interesting I realized today I crash of one of both Tor relays:

Jan 01 11:12:38.000 [warn] compute_weighted_bandwidths(): Bug: Consensus is missing some bandwidths. Using a naive router selection algorithm (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] tor_assertion_failed_(): Bug: src/feature/nodelist/node_select.c:723: compute_weighted_bandwidths: Assertion node->rs->is_possible_guard failed; aborting. (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug: Tor 0.4.2.5: Assertion node->rs->is_possible_guard failed in compute_weighted_bandwidths at src/feature/nodelist/node_select.c:723: . Stack trace: (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(log_backtrace_impl+0x59) [0x55850995e1a9] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(tor_assertion_failed_+0x150) [0x5585099593e0] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(+0x12c474) [0x558509896474] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(frac_nodes_with_descriptors+0x73) [0x558509897373] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(+0x12afb2) [0x558509894fb2] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(count_loading_descriptors_progress+0x6c) [0x558509895b2c] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(connection_dir_reached_eof+0x20e0) [0x558509856f30] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(connection_handle_read+0x980) [0x5585097d2760] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(+0x6d97c) [0x5585097d797c] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/lib64/libevent-2.1.so.6(+0x219ca) [0x7ffbba3cb9ca] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/lib64/libevent-2.1.so.6(event_base_loop+0x4ef) [0x7ffbba3cc54f] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(do_main_loop+0xdd) [0x5585097d8b2d] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(tor_run_main+0x10c5) [0x5585097c6855] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(tor_main+0x46) [0x5585097c4076] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(main+0x19) [0x5585097c3c49] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /lib64/libc.so.6(__libc_start_main+0xeb) [0x7ffbb9d19eab] (on Tor 0.4.2.5 )
Jan 01 11:12:38.000 [err] Bug:     /usr/bin/tor(_start+0x2a) [0x5585097c3c9a] (on Tor 0.4.2.5 )

System is a hardened Gentoo Linux running 2 relays. The second is not affected.