projen: Projen python version default command fails

Hello, guys, thank you for the awesome tool, the nodejs version works perfectly, however, I’m struggling with the Python binary. Simply installed it globally using pipx install projen and running projen, fails with the following error:

➜  ~ projen
Traceback (most recent call last):
  File "/Users/victor/.local/bin/projen", line 10, in <module>
    __jsii_assembly__.invokeBinScript("projen", "projen", sys.argv[1:])
  File "/Users/victor/.local/pipx/venvs/projen/lib/python3.10/site-packages/jsii/_runtime.py", line 52, in invokeBinScript
    response = _kernel.invokeBinScript(pkgname, script, args)
  File "/Users/victor/.local/pipx/venvs/projen/lib/python3.10/site-packages/jsii/_kernel/__init__.py", line 312, in invokeBinScript
    args=_make_reference_for_native(self, args),
  File "/Users/victor/.local/pipx/venvs/projen/lib/python3.10/site-packages/jsii/_kernel/__init__.py", line 204, in _make_reference_for_native
    kernel.create(d.__class__, d)
  File "/Users/victor/.local/pipx/venvs/projen/lib/python3.10/site-packages/jsii/_kernel/__init__.py", line 323, in create
    fqn=klass.__jsii_type__ or "Object",
AttributeError: type object 'tuple' has no attribute '__jsii_type__'

I tried py3.8 and py3.10, and encounter the same result. weird that there is no such issue yet, I’m the only one having this error? Thank you for your help.

About this issue

Original URL
State: closed
Created 2 years ago
Comments: 19 (19 by maintainers)

Commits related to this issue

fix(python): bin script python support, test argument passing (#3762) Corrects multiple issues with running `bin` scripts from python. These were discovered in the context of this `projen` issue: ht... — committed to aws/jsii by jmalins 2 years ago
fix(release): artifact permissions are not preserved in github actions (#2132) Fixes #2103. Due to a bug in GitHub actions, file mode permissions (such as `+x`) are lost between when the build artif... — committed to projen/projen by jmalins 2 years ago
feat(superchain): add 'acl' package to support projen GHA (#3783) Adds the `acl` package to the superchain image. A recent [projen PR](https://github.com/projen/projen/issues/2103) added a build-tim... — committed to aws/jsii by jmalins 2 years ago

Most upvoted comments

And pipx run projen new awscdk-app-py also works! This is great. Good work everyone and especially @jmalins 🥳

mrgrain on Sep 30, 2022

@jmalins thank you very much, I’m impressed. It works!!

floydspace on Sep 30, 2022

I was encountering the same error. It actually looks like it is tied to this change (line 52): https://github.com/aws/jsii/pull/3694/files#diff-8c3c3ced74aeb038ac90c893f7998ce488d3771561a5d253376f9177bcef707c

The arguments for the python script are not being marshaled correctly.

I corrected it in my locally deployed install, and got to the point of finding another error: a missing +x permission on bin/projen in the JSII tarball bundled with python package. Once that was (manually) fixed, the projen executable worked as expected.

I’d like to make a PR, but would still need to navigate the source to figure out where the projen python script is defined and where the tarball is created.

jmalins on Sep 20, 2022

However, in my python environment, I feel like using python tools and not being dependent on nodejs environment. I know eventually implicitly I still depend on it, but better implicitly than explicitly.

I wholeheartedly agree with this sentiment. Binaries for all languages or a standalone binary should be a long-term goal.

Anyway, I think it’s still a bug for python binary, but decide your self should the issue be opened or closed, depends on your plans regarding the projen version for python

We rely on jsii to provide cross-lang capabilities. I can see that we announce projen as an app, so pipx tries to run it. What I’m currently not sure about is if that’s supposed to happen (and we need to fix a bug with running it as an app) or if announcing an app was accidental (and we should stop doing that). If it’s the latter, a long term fix would depend on jsii’s capabilities in that area, or we start shipping a standalone binary.

mrgrain on Sep 13, 2022

Hi @floydspace ! I’m not actually sure this is supposed to work or even possible to work with jsii.

Background: Projen is a TypeScript project with jsii bindings for Python and other languages so that you can write the configuration in the language of your project (or choice). Due to its nature jsii has limitations and running a cli might just be one of them.

tl;dr the expected way to run projen is still via node: npx projen

I appreciate we’re probably not doing the best job explaining this in the documentation.

mrgrain on Sep 13, 2022