Autoconf compiler check breaks Emscripten build

vadimkantorov commented 4 years ago

It cannot discover any compiler output (suffixed as .out.js if no -o option is given) and thus halts ./configure: https://github.com/TeX-Live/texlive-source/blob/trunk/texk/upmendex/configure#L3081 with the message that "compiler cannot create executables"

Other similar compiler checks in other TexLive programs pass without problems. Maybe just need to re-run with a recent autoconf? Unfortunately this check is not cached.

Would you have some ideas how to stub it out by config.site or config.cache?

If needed, I'll prepare a repro (I can repro by building the full TexLive tree for now, will figure out how to make only upmendex)

t-tk commented 4 years ago

Thank you for your comment. In current TeX Live svn repository https://www.tug.org/svn/texlive/trunk/Build/source/texk/upmendex/ , configure is generated by the latest autotools (automake 1.16.2 (2020-03-21) & autoconf 2.69 (2012-04-24)). Karl has kindly updated them at r56843

According to google, an error with the message "compiler cannot create executables" is fixed by installing related compiler software in many cases. https://www.google.com/search?channel=fs&client=ubuntu&q=%22compiler+cannot+create+executables%22 It might be useful information.

vadimkantorov commented 4 years ago

Thanks for your response!

The strange thing is that in all other texlive tools, the compiler check passes successfully. Only upmendex one fails with emcc.

vadimkantorov commented 4 years ago

@t-tk Where should I report this issue? Should I send it to tlbuild mailing list? upmendex clearly uses different compiler check compared to the rest of TexLive

Emscripten compiler of course "can create executables", and I'm able to compile the rest of TexLive without problems. I have compiler well-installed and no additional software is needed, since I'm able to compile other parts of TexLive without issues

vadimkantorov commented 4 years ago

I'll post a full repro in a few days, but maybe even doing autoreconf with fresh autoconf would do the trick...

t-tk commented 4 years ago

I do not know why configure script of upmendex requested emcc or emscripten in your system. In my environment (ubuntu linux), I do not need emcc. In addition, I could not find the word emcc in Travis CI build logs.

upmendex itself is written in C (not C++) language and linked with the ICU library written in C++. The composition might be unique compared to other TeX Live tools. I have no more idea about what make difference.

vadimkantorov commented 4 years ago

I'll post a full repro, hope it would be helpful.

Emscripten/emcc is a cross-compile of C to WebAssembly. TexLive doesn't target WebAssembly in regular builds, as far as I understand. So emcc cannot be found in Tracis CI build logs.

upmendex requested emcc because I specified emcc as a cross-compiler. You may not need emcc, but users who are trying to cross-compile TexLive to WebAssembly do need to use emcc for the time being.