aws_cdk python breaks import of jinja2 module on windows 10 64-bit

[marcelser]

when loading aws_cdk core it breaks the jinja2 templating module on Windows 10 64-bit

Reproduction Steps

• create dummy project with "cdk init -l python"
• import jinja2 module and it errors out on loading with an EOF error

here'a sample

from aws_cdk import core

from jinja2 import Environment, FileSystemLoader

class ClusterTestStack(core.Stack):

    def __init__(self, scope: core.Construct, id: str, **kwargs) -> None:
        super().__init__(scope, id, **kwargs)

        # The code that defines your stack goes here

Error Log

    throw err;
    ^

Error: EOF: end of file, read
    at Object.readSync (fs.js:516:3)
    at SyncStdio.readLine (C:\Users\elserm\devenv\git-projects\environment\cdk-scripts\cluster-test\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:13314:25)
    at InputOutput.read (C:\Users\elserm\devenv\git-projects\environment\cdk-scripts\cluster-test\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:13264:34)
    at KernelHost.run (C:\Users\elserm\devenv\git-projects\environment\cdk-scripts\cluster-test\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:7220:32)
    at Immediate.<anonymous> (C:\Users\elserm\devenv\git-projects\environment\cdk-scripts\cluster-test\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:7228:37)
    at processImmediate (internal/timers.js:439:21) {
  errno: -4095,
  syscall: 'read',
  code: 'EOF'
}

Environment

• CLI Version : 1.16.3 (build 8c7f593)
• Framework Version: 1.16.3
• OS : Windows 10 64-bit
• Language : Python 3.7.5 & nodejs 13.1.0

Other

Interestingly when I just run python cli and do:
"import jinja2 or "from jinja2 import Environment" it works perfectly fine. It's just inside cdk where it breaks miserably and only on windows 10 64-bit. It works perfectly fine on a linux machine of my colleague.

I tried everything like cleaning up and reinstalling python, cleaning up and reinstalling nodejs. Deleting npm and pip caches, re-created .env numerous times, nothing fixes this issue, it's really the aws_cdk core that breaks jinja2.

---

This is 🐛 Bug Report

[eladb]

This is a python specific issue

[marcelser]

This is a python specific issue

Yes, but you support python in cdk so you should fix comptability issues introduced by aws provided python libraries

[eladb]

Absolutely. The reason I noted that was related to our internal assignment. We should definitely look into this!

[garnaat]

Are you using the virtual environment created by the init template?

[marcelser]

For the actual project where we discovered the issue I have created the virtual env using "python -m venv .env" but I think for this minimal example for the bug ticket I think I used the one from the init template but I can't say for sure anymore. But I think it happens in both cases.

But we must be able to re-create the .env anyhow if me move the folder or use it in linux etc. therefore we don't even save the .env for our project in our gitlab repository. If anyone needs to work with it he/she checks out the cdk code and quickly runs "python -m venv .env", activates the venv and then does "pip install -r requirements.txt" and he should be ready to go.

[RomainMuller]

Would you be able to run your reproduction with the JSII_DEBUG=1 environment variable, and provide the output (in a gist, pastebin, ... -- feel free to redact anything you don't want to share) ?

[seziCZ]

I seem to have hit the same problem when testing with unittest:

from aws_cdk import core
import unittest

class TestClass(unittest.TestCase):
    def test_method(self):
        self.assertTrue(True)

if __name__ == '__main__':
    unittest.main()

Running the snippet (as an administrator under Windows Enterprise 10.0.18363, Build 18363) results in following stack trace (JSII_DEBUG enabled):

(.env) c:\Sources\Aws>python -m unittest
> {"name":"@aws-cdk/cloud-assembly-schema","version":"1.47.0","tarball":"c:\\Sources\\Aws\\.env\\lib\\site-packages\\aws_cdk\\cloud_assembly_schema\\_jsii\\cloud-assembly-schema@1.47.0.jsii.tgz","api":"load"}
[@jsii/kernel] load {
  name: '@aws-cdk/cloud-assembly-schema',
  version: '1.47.0',
  tarball: 'c:\\Sources\\Aws\\.env\\lib\\site-packages\\aws_cdk\\cloud_assembly_schema\\_jsii\\cloud-assembly-schema@1.47.0.jsii.tgz',
  api: 'load'
}
[@jsii/kernel] creating jsii-kernel modules workdir: C:\Users\TOMAS~1.SEZ\AppData\Local\Temp\jsii-kernel-qosnry
< {"ok":{"assembly":"@aws-cdk/cloud-assembly-schema","types":31}}
> {"name":"@aws-cdk/cx-api","version":"1.47.0","tarball":"c:\\Sources\\Aws\\.env\\lib\\site-packages\\aws_cdk\\cx_api\\_jsii\\cx-api@1.47.0.jsii.tgz","api":"load"}
[@jsii/kernel] load {
  name: '@aws-cdk/cx-api',
  version: '1.47.0',
  tarball: 'c:\\Sources\\Aws\\.env\\lib\\site-packages\\aws_cdk\\cx_api\\_jsii\\cx-api@1.47.0.jsii.tgz',
  api: 'load'
}
< {"ok":{"assembly":"@aws-cdk/cx-api","types":25}}
> {"name":"constructs","version":"3.0.4","tarball":"c:\\Sources\\Aws\\.env\\lib\\site-packages\\constructs\\_jsii\\constructs@3.0.4.jsii.tgz","api":"load"}
[@jsii/kernel] load {
  name: 'constructs',
  version: '3.0.4',
  tarball: 'c:\\Sources\\Aws\\.env\\lib\\site-packages\\constructs\\_jsii\\constructs@3.0.4.jsii.tgz',
  api: 'load'
}
< {"ok":{"assembly":"constructs","types":13}}
> {"name":"@aws-cdk/core","version":"1.47.0","tarball":"c:\\Sources\\Aws\\.env\\lib\\site-packages\\aws_cdk\\core\\_jsii\\core@1.47.0.jsii.tgz","api":"load"}
[@jsii/kernel] load {
  name: '@aws-cdk/core',
  version: '1.47.0',
  tarball: 'c:\\Sources\\Aws\\.env\\lib\\site-packages\\aws_cdk\\core\\_jsii\\core@1.47.0.jsii.tgz',
  api: 'load'
}
< {"ok":{"assembly":"@aws-cdk/core","types":156}}
.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK
[@jsii/kernel] removing install dir C:\Users\TOMAS~1.SEZ\AppData\Local\Temp\jsii-kernel-qosnry

(.env) c:\Sources\Aws>c:\Sources\Aws\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:13612
                    throw e;
                    ^

Error: EOF: end of file, read
    at Object.readSync (fs.js:577:3)
    at SyncStdio.readLine (c:\Sources\Aws\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:13587:33)
    at InputOutput.read (c:\Sources\Aws\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:13537:34)
    at KernelHost.run (c:\Sources\Aws\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:7372:32)
    at Immediate.<anonymous> (c:\Sources\Aws\.env\lib\site-packages\jsii\_embedded\jsii\jsii-runtime.js:7380:37)
    at processImmediate (internal/timers.js:456:21) {
  errno: -4095,
  syscall: 'read',
  code: 'EOF'
}

Virtual environment created by the init sample-app template was used, together with dependencies listed in autogenerated requirements.txt:

(.env) c:\Sources\Aws>pip freeze
atomicwrites==1.4.0
attrs==19.3.0
-e c:\sources\aws\aws
aws-cdk.assets==1.47.0
aws-cdk.aws-cloudwatch==1.47.0
aws-cdk.aws-ec2==1.47.0
aws-cdk.aws-events==1.47.0
aws-cdk.aws-iam==1.47.0
aws-cdk.aws-kms==1.47.0
aws-cdk.aws-lambda==1.47.0
aws-cdk.aws-logs==1.47.0
aws-cdk.aws-s3==1.47.0
aws-cdk.aws-s3-assets==1.47.0
aws-cdk.aws-sns==1.47.0
aws-cdk.aws-sns-subscriptions==1.47.0
aws-cdk.aws-sqs==1.47.0
aws-cdk.aws-ssm==1.47.0
aws-cdk.cloud-assembly-schema==1.47.0
aws-cdk.core==1.47.0
aws-cdk.cx-api==1.47.0
aws-cdk.region-info==1.47.0
cattrs==1.0.0
colorama==0.4.3
constructs==3.0.4
jsii==1.7.0
more-itertools==8.4.0
packaging==20.4
pluggy==0.13.1
publication==0.0.3
py==1.9.0
pyparsing==2.4.7
pytest==5.4.3
python-dateutil==2.8.1
six==1.15.0
typing-extensions==3.7.4.2
wcwidth==0.2.5

[laimonassutkus]

Any news?

[paujim]

I'm getting this issue without importing jinja2 module. After upgrading to v1.71.0 in windows OS with python 3.8

[RomainMuller]

Yeah, according to my research in #11314, this appears to be related to yet another instance of node standard library having a slightly different behavior on Windows than other platforms (and I do believe this particular instance is definitely a bug in node).

[github-actions]

This issue has not received any attention in 1 year. If you want to keep this issue open, please leave a comment below and auto-close will be canceled.