building boost with emscripten on windows

Question

I am trying to build boost using emscripten on windows. In particular, I am trying to use the emscripten toolset as suggested in https://stackoverflow.com/a/47751199/5969590. However, this produces the following error for me:

C:\dev\emsdk\python\3.9.2-1_64bit\python.exe: can't open file 'c:\dev\boost_1_76_0\emcc.py': [Errno 2] No such file or directory

Somewhere in the toolchain boost tries to invoke emcc.py using python, but fails by passing the wrong module path (there is no emcc.py in c:\dev\boost_1_76_0\).

• I made sure path environment variables are setup correctly by executing emsdk_env.bat. Running emcc.bat (which internally runs emcc.py) manually, executes the compiler as expected.
• I inserted some debug printouts in emcc.bat and from that I gather that the boost toolchain is not using that file. It seems it tries to use python and emcc.py directly. This seems to be where things break down.

Any help or hint is greatly appreciated.

Best, David

Answer 1

Problem was related to this: What is the reason for batch file path referenced with %~dp0 sometimes changes on changing directory?

I solved the problem by hacking emcc.bat to use hardcoded path to the emcc.py file.