Boost no longer builds starting with 4.0.22

[jrxpana]

One of the changes in 4.0.22 was the removal of the em++ and emcc script files (with no extension) in the emsdk distributions for Windows.

Unfortunately, boost seems to use at least one of these files for detection when you use b2.exe to build with toolset=emscripten.

So starting with 4.0.22 our boost builds began to fail unless we manually created an empty emcc and em++ file in the emsdk\upstream\emscripten folder. I suspect we only needed emcc but we created them both just in case because it's really hard to tell what boost is doing when it builds.

I will report this to boost as well, although in the meantime the fix seems to be creating the missing file stubs before building.

[sbc100]

I assume this is windows-only/windows-specific thing?

Would fixing boost upstream be an option here?

BTW, the files with no extension are shell scripts, which don't normally run on windows (at least not in cmd.exe). Are you referring to building boost in some kind mingw or cygwin environment?

[jrxpana]

I don't know that it's Windows specific, other than the fact that those files no longer exist on Windows. I think something about the way boost sets itself up is looking for that file by name, with no extension. And when it doesn't find the file, the build environment isn't set up properly.

So it's not that we need the file so it can run, it's because something is looking specifically for it.

I'm working through this on the boost side at bfgroup/b2#568 , they know a lot better than I do how all this fits together.

[sbc100]

Yes, the un-suffixed file still exists in the non-windows distributions so this would be a windows-only issue.