Bug report

Bug description:

While working on something else, I tripped the conditional that made https://github.com/python/cpython/blob/f589f26/.github/workflows/build_msi.yml start and the workflow run failed. I asked @hugovk to trigger a manual run to make sure it wasn't related to my pull request. Turned out, it currently fails on main and 3.13:

• https://github.com/python/cpython/actions/runs/9964214870/job/27532003707#step:3:4547
• https://github.com/python/cpython/actions/runs/9964214870/job/27532003707#step:3:4547

The last successes recorded were seen about a month ago:

• https://github.com/python/cpython/actions/runs/9352272467
• https://github.com/python/cpython/actions/runs/9521625545

It looks like there are several failures in the logs. The first one seems to be related to missing (or misplaced/corrupted?) blurb (but there seem to be more, maybe related to free-treading — it was hard to judge from the build log):

  py -3.12 -m pip install -U blurb
  Requirement already satisfied: blurb in c:\hostedtoolcache\windows\python\3.12.4\x64\lib\site-packages (1.2.0)
  py -3.12 -m blurb merge -f "D:\a\cpython\cpython\PCbuild\arm64\NEWS.txt"
  Traceback (most recent call last):
    File "<frozen runpy>", line 198, in _run_module_as_main
    File "<frozen runpy>", line 88, in _run_code
    File "C:\hostedtoolcache\windows\Python\3.12.4\x64\Lib\site-packages\blurb\__main__.py", line 6, in <module>
      blurb.main()
      ^^^^^^^^^^
  AttributeError: module 'blurb' has no attribute 'main'

cc @zooba — I understand you're maintaining this workflow, so I'm tagging you for visibility

CPython versions tested on:

CPython main branch

Operating systems tested on:

Windows