Please include the following in your bug report:

Version of emscripten/emsdk:
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.33 (c1927f2)
clang version 17.0.0 (https://github.com/llvm/llvm-project 671eeece457f6a5da7489f7b48f7afae55327b8b)
Target: wasm32-unknown-emscripten
Thread model: posix

Description

• On Windows, emcc when triggered, the command resolves to emcc.bat.
• emcc.bat in turn looks for emcc.py in the same directory using "%~dp0\%~n0.py"
• When invoked with quotes ("emcc"), the resolution of "%~dp0\%~n0.py" in emcc.bat causes issues, as shown in the following links:
  • https://stackoverflow.com/questions/67245300/building-boost-with-emscripten-on-windows
  • https://stackoverflow.com/questions/12141482/what-is-the-reason-for-batch-file-path-referenced-with-dp0-sometimes-changes-o
• One such case, in which emcc is called with quotes is when building boost for emscripten using the b2 tool.

Possible Solution

• Since the path to emsdk is available in the EMSDK environment variable, it can be used to replace "%~dp0\%~n0.py" with "%EMSDK%\upstream\emscripten\%~n0.py