[tahoe-lafs-trac-stream] [Tahoe-LAFS] #4190: Broken tests: failUnlessRaises has been deprecated

[Tahoe-LAFS]

#4190: Broken tests: failUnlessRaises has been deprecated
-------------------------------+---------------------------
     Reporter:  hacklschorsch  |      Owner:  hacklschorsch
         Type:  defect         |     Status:  assigned
     Priority:  normal         |  Milestone:  undecided
    Component:  unknown        |    Version:  n/a
   Resolution:                 |   Keywords:
Launchpad Bug:                 |
-------------------------------+---------------------------

Old description:

> `failUnlessRaises` has been deprecated in favor of `assertRaises`.
>
> This breaks tests (see https://app.circleci.com/pipelines/github/tahoe-
> lafs/tahoe-lafs/5377/workflows/cd00a81d-54c3-43be-8041-719ea727c3f1).
>
> Thanks @sajith for the pointer (both to the broken tests and the possible
> cause)!

New description:

 `failUnlessRaises` has been deprecated in favor of `assertRaises`.

 This breaks tests (see https://app.circleci.com/pipelines/github/tahoe-
 lafs/tahoe-lafs/5377/workflows/cd00a81d-54c3-43be-8041-719ea727c3f1).

 Thanks @sajith for the pointer (both to the broken tests and the possible
 cause)!

 {{{
 2025-12-30 20:51:45 hacklschorsch   sajith: thanks for your link to >
 https://app.circleci.com/pipelines/github/tahoe-lafs/tahoe-
 lafs/5377/workflows/cd00a81d-54c3-43be-8041-719ea727c3f1
 2025-12-30 20:53:20 hacklschorsch   Seems most failures here are due to
 "[...] object has no attribute 'failUnlessRaises'" - Maybe some dependency
 has changed?
 2025-12-30 20:55:31 hacklschorsch   (in the windows builds)
 2025-12-30 20:55:38 hacklschorsch   IIRC these worked until a while ago
 2025-12-30 21:43:49 sajith  hacklschorsch: I am not 100% sure right now,
 but I think Python (unittest module maybe?) has deprecated
 failUnlessRaises in favor of assertRaises or something, and I suspect that
 we've ended up importing failUnlessRaises both from twisted.trial.unittest
 and stdlib unittest. Just a hypothesis. I don't have the time to check
 right now.
 }}}

--

Comment (by hacklschorsch):

 I was able to reproduce the behavior on my NixOS development machine with
 a `3.13.9` CPython.

 Replacing all occurrences of `failUnlessRaises` with `assertRaises` fixes
 this problem.

--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/4190#comment:3>
Tahoe-LAFS <https://Tahoe-LAFS.org>
secure decentralized storage