fix 'set EM_PY' in batch files

[fs-eire]

This fixes the following error:

  '"python"' is not recognized as an internal or external command,

This is not usually triggered because usually EMSDK_PYTHON is set.

[sbc100]

These files are all auto-generated by create_entry_points.py, so if you want to make changes that is the place to start.

Does cmd.exe not look for python.exe automatically when you type just python?

Isn't it better to use the bare python string since then the cmd.exe shell will also look for things like python.bat and python.com?

[fs-eire]

Does cmd.exe not look for python.exe automatically when you type just python?

Isn't it better to use the bare python string since then the cmd.exe shell will also look for things like python.bat and python.com?

I ran into this issue when trying to use vcpkg with emscripten in my project. I don't know much about this parts so not sure about the answer to your questions. The direct error I saw is emcc.bat failed because of the error.

Let me do some further investigation.

[sbc100]

Does cmd.exe not look for python.exe automatically when you type just python?
Isn't it better to use the bare python string since then the cmd.exe shell will also look for things like python.bat and python.com?

I ran into this issue when trying to use vcpkg with emscripten in my project. I don't know much about this parts so not sure about the answer to your questions. The direct error I saw is emcc.bat failed because of the error.

Let me do some further investigation.

How are you installing/using emscripten? Are you not using emsdk?

Where is python.exe coming from on your system? i.e what does where python say?

[fs-eire]

Close this one. The root cause is that environment variables are not inherited when using vcpkg. It’s not something we should fix in emscripten.