PyYAML pip import fails with python3 about rules_python HOT 16 CLOSED

We need something like a py_toolchain target in Bazel so that it actually knows what version of Python it's invoking. See py_toolchain draft proposal

from rules_python.

Also, I'd love to see @joshclimacell's patch in this repo.

from rules_python.

It looks like PyYAML selects which tree to install based upon the version of Python that is currently running: https://github.com/yaml/pyyaml/blob/master/setup.py#L287 . Is is possible that Bazel isn't running setup.py under the same version of python specified in --python_path?

from rules_python.

Yes, that's exactly right. Unfortunately this will be hard to fix, since Bazel is in a "transition" state right now regarding how it handles multiple Python interpreters, but we can take a look to see if there is a workaround.

from rules_python.

One workaround that immediately comes to mind is:

1. Use ruamel instead of PyYaml, it's a drop-in replacement (PyYaml was abandoned, ruamel was forked, then PyYaml came back to life, not sure of the current status).

from rules_python.

Ignore my previous workaround # 1, reading comprehension fail.

We have this same issue internally in Blaze, but the specifics and the fix are different.

from rules_python.

@duggelz It sounds like there's a dependency on some Bazel work, then. Is there a Bazel issue one could follow for that work? Any ETA, or is it just "this should get done sometime, we don't know when"?

from rules_python.

@duggelz I've worked around my local issue by just using ruamel (thanks for the pointer!), so this isn't a pressing problem for me right now.

However, it still feels like we'd want to solve this in the general case, for times when there isn't going to be a workaround.

from rules_python.

@duggelz @mattmoor It looks like this might also be related to bazelbuild/bazel#3871 ?

from rules_python.

Ping. I'm still interested in helping get this fixed, but need a few pointers.

from rules_python.

Ping...

from rules_python.

For reference, I implemented a (not-super-awesome, but functioning) workaround for loading Python 3 PyPi packages: joshclimacell@90a70d5

from rules_python.

This affects tornado as well. Its setup.py selectively adds dependencies depending on the runtime version of Python detected. The concurrent library is not Python 3 compatible, and breaks the runtime.

from rules_python.

So, I noticed that there's not only a duplicate issue for this (#62), but there's also a duplicate PR for this one (#82). Can one of the project maintainers (@mattmoor ? @duggelz ?) help get this reconciled?

from rules_python.

Any update on this?

from rules_python.

Using this as repro to merge (a rebase of) #85; work toward #249.

from rules_python.