Crash on Sync - Unknown Exception

Mailspring 1.7.1 and later has a sync crash with no stack trace. This appears on Windows, Mac, and Linux.

joshnewans on GitHub provided the following stack trace on Linux and 1.7.2.

14610 [2019-10-25 14:14:34.916] [main] [info] Identity created at 1554039823 - using ID Schema 1
14610 [2019-10-25 14:14:34.917] [main] [info] ------------- Starting Sync (xxxxx@xxxxx.xxxx) ---------------
14610 [2019-10-25 14:14:34.920] [metadata] [info] Metadata delta stream starting...
14610 [2019-10-25 14:14:37.920] [background] [info] Marking all folders as `busy`
14610 [2019-10-25 14:14:37.936] [background] [info] Syncing folder list...
14610 [2019-10-25 14:14:38.090] [background] [info] Syncing folder list...
14610 [2019-10-25 14:14:38.166] [background] [info] syncFolderUIDRange for INBOX, UIDs: 1 - 12905, Heavy: true
14610 [2019-10-25 14:14:38.441] [foreground] [info] syncFolderUIDRange for INBOX, UIDs: 13551 - 13667, Heavy: false
14610 [2019-10-25 14:14:38.520] [foreground] [info] - remote=101, local=101
14610 [2019-10-25 14:14:38.532] [foreground] [info] Idling on folder INBOX
14610 [2019-10-25 14:14:49.921] [metadataExpiration] [info] Scanning for expired metadata
14610 [2019-10-25 14:14:49.921] [metadataExpiration] [info] -- Will wake for next expiration in 7200sec
14610 [2019-10-25 14:14:54.876] [] [critical] 
 ***
 *** An exception occurred during program execution: 
 *** (unknown exception details)
 ***

14610 [2019-10-25 14:14:54.893] [] [critical]  *** Stack trace (line numbers are approximate):
 *** (unknown)  clone
 ***

This may or may not be related to:

I am seeing crash on sync multiple times every day, and am about to be forced to cancel my subscription and move on…