$ offlineimap -c ~/.config/offlineimap/offlineimap.conf 
/usr/lib/python3/site-packages/offlineimap/repository/IMAP.py:548: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if foldername is '':
/usr/lib/python3/site-packages/offlineimap/imapserver.py:105: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  and self.tlslevel is not "tls_compat" \
OfflineIMAP 7.3.3
  Licensed under the GNU GPL v2 or any later version (with an OpenSSL exception)
imaplib2 v2.101 (bundled), Python v3.9.6, OpenSSL 1.1.1n  15 Mar 2022
Account sync basealt:
 *** Processing account basealt
 Establishing connection to air.basealt.ru:993 (basealt-imap)
 ERROR: While attempting to sync account 'basealt'
  IMAP4 protocol error: program error: <class 'TypeError'> - cannot use a bytes pattern on a string-like object
 *** Finished account 'basealt' in 0:00
ERROR: can't have text and binary mode at once
ERROR: Exceptions occurred during the run!
ERROR: While attempting to sync account 'basealt'
  IMAP4 protocol error: program error: <class 'TypeError'> - cannot use a bytes pattern on a string-like object

Traceback:
  File "/usr/lib/python3/site-packages/offlineimap/accounts.py", line 293, in syncrunner
    self.__sync()
  File "/usr/lib/python3/site-packages/offlineimap/accounts.py", line 372, in __sync
    remoterepos.getfolders()
  File "/usr/lib/python3/site-packages/offlineimap/repository/IMAP.py", line 452, in getfolders
    imapobj = self.imapserver.acquireconnection()
  File "/usr/lib/python3/site-packages/offlineimap/imapserver.py", line 557, in acquireconnection
    imapobj = imaplibutil.WrappedIMAP4_SSL(
  File "/usr/lib/python3/site-packages/offlineimap/imaplibutil.py", line 202, in __init__
    super(WrappedIMAP4_SSL, self).__init__(*args, **kwargs)
  File "/usr/lib/python3/site-packages/offlineimap/bundled_imaplib2.py", line 2191, in __init__
    IMAP4.__init__(self, host, port, debug, debug_file, identifier, timeout, debug_buf_lvl)
  File "/usr/lib/python3/site-packages/offlineimap/bundled_imaplib2.py", line 399, in __init__
    self.welcome = self._request_push(name='welcome', tag='continuation').get_response('IMAP4 protocol error: %s')[1]
  File "/usr/lib/python3/site-packages/offlineimap/bundled_imaplib2.py", line 200, in get_response
    raise typ(exc_fmt % str(val))

ERROR: can't have text and binary mode at once