Twisted 25.5.0 (2025-06-07)

Bugfixes

• twisted.internet.runner.procmon.ProcessMonitor: startProcess() catches
  exceptions raised by reactor.spawnProcess() and attempts to restart
  the failed process. (#12421)

Deprecations and Removals

• twisted.trial.unittest.TestCase.deferSetUp,
  twisted.trial.unittest.TestCase.deferTestMethod,
  twisted.trial.unittest.TestCase.deferTearDown, and
  twisted.trial.unittest.TestCase.deferRunCleanups were removed and
  converted to private methods. These functions expose so much of the
  internal structure of TestCase that it makes the code hard to change.
  (#12388)
• twisted.internet.defer.waitForDeferred
  twisted.internet.defer.deferredGenerator have been removed. They have
  been deprecated since Twisted 15.0.0 (#12404)
• twisted.internet.defer.Deferred.callbacks attribute has been
  deprecated. (#12407)

Misc

• #12375, #12383, #12384, #12392, #12419, #12434, #12440, #12441

Conch

Bugfixes

• twisted.conch.client.direct.SSHClientTransport.verifyHostKey no longer
  crashes with an encoding error while attempting to verify the peer's
  IP address. This means that the conch
  command-line tool will no longer fail host key verification with 'bad
  host key' when using a known hosts file containing only plaintext,
  rather than hashed, hostnames. (#12414)

Web

Features

• The twisted.web.websockets module has been added, adding a websockets
  server and client based on the wsproto library. (#4173)
• twisted.web.server.Site can now be created with a
  parsePOSTFormSubmission=False parameter to disable parsing of HTTP
  request bodies. (#12412)

Bugfixes

• twisted.web.http.Request.addCookie now supports the
  none value for cookie's
  samesite attribute. (#10088)
• twisted.web.http.Request.requestReceived now handles multiple files in
  multipart/form-data with the same "name" parameter. This was a
  regression introduced in Twisted 24.3.0. (#12423) (#12423)

Improved Documentation

• An error in the example for using a Resource object in th
  documentation on Configuring and Using the Twisted Web Server has been
  correctd.

  Furthermore, a number of references to "strings" where "bytes" where
  expected has been adjusted. (#12410)

Mail

Bugfixes

• twisted.mail.mail.MailService.addDomain now adds the given domain's
  credential checkers to the service's portal, allowing users to
  authenticate to the domain. (#12431)

Words

No significant changes.

Names

No significant changes.

Trial

Bugfixes

• twisted.trial.unittest.TestCase.addCleanup will cause the test to fail
  if the returned deferred is not resolved before the test's timeout.
  (#12390)