poetry run causes [FileNotFoundError] with some scripts

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: Windows 10 Enterprise
• Poetry version: Poetry version 1.0.5
• Link of a Gist with the contents of your pyproject.toml file: https://gist.github.com/huwper/efb95344f986939bf4fd717fbeb64a91

Issue

Using poetry run to run scripts fails on some scripts. I think this is probably in cases where the script has no file extension. The linked pyproject.toml installs scons into the virtual environment. Scons comes with a script called scons which is installed in the Scripts directory. The following error occurs when running the script:

c:\Projects\personal\poetry-scons-issue>poetry run scons

[FileNotFoundError]
[WinError 2] The system cannot find the file specified

Running poetry venv info to get path/to/venv and running scons with the explicit path works fine

> path\to\venv\Scripts\scons

scons: *** No SConstruct file found.
......

scons also comes with a script called scons.bat which does the same thing. poetry run scons.bat does work

[kevincon]

I think this is also a duplicate of #3265 which I have this PR up to fix: #3339

[andschwa]

@sinoroc Yes, I think these are all the same issue. I have a question: what’s then intention behind env.py’s _bin(bin) method? I inferred that it’s to check Poetry’s virtualenv first (that’s what the code sure is doing by looking at self._bin_dir / bin first, and only falling back to bin if nothing was found in self._bin_dir). If this is indeed the case, that lends credence to my recommendation I made here: https://github.com/python-poetry/poetry/pull/3395#issuecomment-732546336

@kevincon @huwper Can you both take a look and confirm? I definitely borrowed from both your PR’s and am happy to go change the authorship. In fact, let me go do that! This was definitely a joint effort.