AttributeError: property 'file' of 'IMAP4WithTimeout' object has no setter (Python 3.14)

[kunesj]

IMAP4WithTimeout is broken on Python 3.14 with imapclient 3.1.0.

Traceback:

  File "/home/jirka642/PycharmProjects/odoo_17/messaging/.venv/lib/python3.14/site-packages/imapclient/imapclient.py", line 288, in __init__
    self._imap = self._create_IMAP4()
                 ~~~~~~~~~~~~~~~~~~^^
  File "/home/jirka642/PycharmProjects/odoo_17/messaging/.venv/lib/python3.14/site-packages/imapclient/imapclient.py", line 332, in _create_IMAP4
    return imap4.IMAP4WithTimeout(self.host, self.port, connect_timeout)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jirka642/PycharmProjects/odoo_17/messaging/.venv/lib/python3.14/site-packages/imapclient/imap4.py", line 13, in __init__
    imaplib.IMAP4.__init__(self, address, port)
    ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.14/imaplib.py", line 208, in __init__
    self.open(host, port, timeout)
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "/home/jirka642/PycharmProjects/odoo_17/messaging/.venv/lib/python3.14/site-packages/imapclient/imap4.py", line 22, in open
    self.file = self.sock.makefile("rb")
    ^^^^^^^^^
AttributeError: property 'file' of 'IMAP4WithTimeout' object has no setter

I have been able to hotfix it like this, but that might not be the correct way to do it:

class FixedIMAP4WithTimeout(imaplib.IMAP4):
    def __init__(self, host: str = "", port: int = 143, timeout: float | None = None) -> None:
        self._timeout = timeout
        super().__init__(host=host, port=port, timeout=timeout)

    def _create_socket(self, timeout: float | None = None) -> socket.socket:
        timeout = timeout if timeout is not None else self._timeout
        return super()._create_socket(timeout=timeout)


class FixedIMAPClient(imapclient.IMAPClient):
    def _create_IMAP4(self) -> imaplib.IMAP4:
        if not self.stream and not self.ssl:
            connect_timeout = getattr(self._timeout, "connect", None)
            return FixedIMAP4WithTimeout(self.host, self.port, connect_timeout)
        return super()._create_IMAP4()

[kunesj]

#618 had similar issue that has already been fixed

[jaglac]

Thank you for posting the hotfix code @kunesj! I used it successfully but also had to overwrite the IMAPClient.starttls() method to remove this line, which also tries to set the .file attr that has been made read-only: https://github.com/mjs/imapclient/blob/master/imapclient/imapclient.py#L387

[kunesj]

I think just removing the line could break things? Setting the private attribute self._imap._file could be safer, but the correct way to fix it would probably be to use the self._imap.starttls(ssl_context=ssl_context) method, but I have not tested that.

Maybe something like this?

@require_capability("STARTTLS")
def starttls(self, ssl_context=None):
    if self.ssl or self._starttls_done:
        raise exceptions.IMAPClientAbortError("TLS session already established")

    typ, data = self._imap.starttls(ssl_context=ssl_context)
    self._checkok("starttls", typ, data)

    self._starttls_done = True
    return data[0]

[jaglac]

Ah, thanks for pointing that out! My code was already calling the method with a pre-defined ssl.SSLContext via imap_client_instance.starttls(ssl_context=ssl_context_object), so that may be why I was able to just comment out that line and move on. I just tried your suggestion within the same pipeline and it was also successful for my one intended use-case.

[736-c41-2c1-e464fc974]

Having the same issue here, tried to fix this with #641