can't read incoming message: Geary loops with "Claiming folder session"
I tried running Geary built from git mainline on Ubuntu 20.04.
As a test, I sent a message to myself (in my Gmail account). When I try to read the message, its text doesn't appear in the conversation viewer. Geary seems to be in an infinite loop with log output that looks like this:
[deb] 18:41:31.0874 Geary: [goa_account_1591587948_1] [>Archive, open_count=1, remote_opened=true] GearyImapEngineOtherFolder: Claiming folder session
[deb] 18:41:31.0884 Geary: [goa_account_1591587948_1] [>Archive, open_count=1, remote_opened=true] GearyImapEngineOtherFolder: Claiming folder session
[deb] 18:41:31.0893 Geary: [goa_account_1591587948_1] [>Archive, open_count=1, remote_opened=true] GearyImapEngineOtherFolder: Claiming folder session
[deb] 18:41:31.0911 Geary: [goa_account_1591587948_1] [>Archive, open_count=1, remote_opened=true] GearyImapEngineOtherFolder: Claiming folder session
[deb] 18:41:31.0921 Geary: [goa_account_1591587948_1] [>Archive, open_count=1, remote_opened=true] GearyImapEngineOtherFolder: Claiming folder session
[deb] 18:41:31.0931 Geary: [goa_account_1591587948_1] [>Archive, open_count=1, remote_opened=true] GearyImapEngineOtherFolder: Claiming folder session
[deb] 18:41:31.0934 Geary: [goa_account_1592905834_0] [>Follow up, open_count=1, remote_opened=true] ...
...
Here's a complete log: geary.log
This happens repeatably, every time I start Geary.