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Fixed in 2020.3.40f1



Found in


Issue ID




[WebGL][BuildError] Constant il2cpp build error after OSX 12.3 Upgrade



On a macOS computer with macOS 12.3:
1. Create a new empty 3D project
2. Switch platform to WebGL
3. Build

What happens: the following build error occurs:
When building for WebGL target, constantly get the error
System.ComponentModel.Win32Exception (2): No such file or directory
at System.Diagnostics.Process.ForkAndExecProcess(String filename, String\[] argv, String\[] envp, String cwd, Boolean redirectStdin, Boolean redirectStdout, Boolean redirectStderr, Boolean setCredentials, UInt32 userId, UInt32 groupId, UInt32\[] groups, Int32& stdinFd, Int32& stdoutFd, Int32& stderrFd, Boolean usesTerminal, Boolean throwOnNoExec)
at System.Diagnostics.Process.StartCore(ProcessStartInfo startInfo)
at System.Diagnostics.Process.Start()
at Unity.IL2CPP.Shell.SetupAndStart(ExecuteContext context, Boolean asyncMode) in /Users/bokken/build/output/unity/il2cpp/Unity.IL2CPP.Shell/Shell.cs:line 423

Repro on 2020.3.31f1
Not repro on trunk 2022.2.0a9

Only repro on macOS 12.3
Not repro on Windows

Comments (6)

  1. owensavag8

    Dec 16, 2022 16:47

    Some real bullshit if anyone finds a solution that works let me know

  2. CengageJermAker

    Apr 12, 2022 17:09

    Python 3.10.2 installed via Homebrew and this fixed mine:
    Environment.SetEnvironmentVariable("EMSDK_PYTHON", "/usr/local/Cellar/python@3.10/3.10.2/Frameworks/Python.framework/Versions/3.10/bin/python3.10");

  3. simon_zappar

    Apr 01, 2022 20:22

    Thanks for the hint Dmitrov.

    So the issue is macOS 12.3 dropped the /usr/bin/python executable.

    The version of emscripten in 2020.3 is pretty old but does support python2 or python3.

    So the fix for me was to open /Applications/Unity/Hub/Editor/2020.3.31f1/PlaybackEngines/WebGLSupport/BuildTools/Emscripten/emcc in a text editor, and change the first line to: #!/usr/bin/env python3

  4. dimitroff

    Mar 29, 2022 11:22

    For a temporary fix, install python 2.7 and then make a pre-build editor script to set the EMSDK_PYTHON env variable.

    In my case it looks like this:

    public class PreBuildProcessing : IPreprocessBuildWithReport
    public int callbackOrder => 1;

    public void OnPreprocessBuild(BuildReport report)
    System.Environment.SetEnvironmentVariable("EMSDK_PYTHON", "/Library/Frameworks/Python.framework/Versions/2.7/bin/python");

  5. adowtatepmar

    Mar 25, 2022 19:03

    Not fixed after installing python 2.7

  6. M_R_Antonio

    Mar 25, 2022 07:06

    Exact same happening here

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