You'll need the latest wasmer RC for proper exceptions support.

We unfortunately didn't get the final release out quite in time...

    curl https://get.wasmer.io -sSfL | sh -s "v6.1.0-rc.5"
    wasmer run python/python

▲ simonw 7 hours ago | parent [-]

How long should it take for "wasmer run python/python" to start showing me output? It's been hung for a while for me now (I upgraded to wasmer 6.1.0-rc.5).

"wasmer run python/python@=0.2.0" on the same machine gets me into Python 3.12.0 almost instantly.

▲ the_duke 7 hours ago | parent [-]

Compilation with LLVM takes quite a while (the final release will show a spinner...).

So please wait a bit - subsequent runs will be fast, since compiled Python will be cached.

▲ simonw 7 hours ago | parent [-]

Oh so it's actually compiling everything on my machine?

Any chance `wasmer run python/python` might download a pre-compiled version in the future?

▲ the_duke 7 hours ago | parent [-]

Yeah, that's mentioned as a small side note in the blog post - we are working on it, and will hopefully have it ready in a week or two!

▲ simonw 7 hours ago | parent [-]

OK got there in the end! I didn't time it but felt like around 10 minutes or more.

It did give me one warning message:

  % wasmer run python/python
  Python 3.13.0rc2 (heads/feat/dl-dirty:152184da8f, Aug 28 2025, 23:40:30) [Clang 21.1.0-rc2 (git@github.com:wasix-org/llvm-project.git 70df5e11515124124a4 on wasix
  Type "help", "copyright", "credits" or "license" for more information.
  warning: can't use pyrepl: No module named 'msvcrt'
  >>>

▲

shakna 4 hours ago | parent [-]

That sounds like the compilation is accidentally triggering this old frustration [0].

[0] https://github.com/python/cpython/issues/131189

▲

behnamoh 2 hours ago | parent [-]

Compilation was slow for me on macOS too.

	▲	syrusakbary an hour ago \| parent [-]
		We'll improve this very soon, right now the experience is less than ideal. Ideally we would download the compiled artifacts instead of compiling as Simon commented... it will be a much better experience for everyone!