complie error with "./tangleboot tangle tangle"

[ElijahGodrand]

Meet a very strange problem:

1. ENV: ubuntu 20.04, gcc-9, g++-9, emsdk 1.38.33-upstream

2. Problem:

WEBINPUTS=.:/home/kw/texlive.js-master/pdftex-1.40.11/src/texk/web2c WEBINPUTS=.:/home/kw/texlive.js-master/pdftex-1.40.11/src/texk/web2c TEXMFCNF=/home/kw/texlive.js-master/pdftex-1.40.11/src/texk/web2c/../kpathsea ./tangleboot tangle tangle
warning: kpathsea: configuration file texmf.cnf not found in these directories: /home/kw/texlive.js-master/pdftex-1.40.11/src/texk/web2c/../kpathsea.
./tangleboot: fatal: web file `tangle.web' not found.
make[1]: *** [Makefile:8738：tangle.p] error 1
make[1]: leave “/home/kw/texlive.js-master/pdftex-1.40.11/build-pdftex/texk/web2c”

Since the problem, compling can not generate pdftex

3. My analycis

3.1 There is another "tangleboot" in "binary/pdftex-1.40.11/build-pdftex/texk/web2c/tangleboot". It was complied by gcc. I tested it, it run ok. It can generate "tangle.p".

3.2 I try mangy method to tell "texlive.js-master/pdftex-1.40.11/src/texk/web2c/tangboot" the path of files, such as absolute path, coping tangle.web tangle.ch texmf.cnf to texlive.js-master/pdftex-1.40.11/src/texk/web2c/tangboot, and so on. ALL don't work. Since it was complied by emsdk (emcc). I think, the reason of the problem may be emsdk can't read and write local file.

4. Possible solution
   Since "binary/pdftex-1.40.11" has the right generated "tangle.p", may we should rewrite configurate and generate new Makefile, and use emsdk compile binary/pdftex-1.40.11 to avoid "tangleboot tangle tangle" error. Alos, may we can directly copy "tangle.p" from "binary/pdftex-1.40.11" to "texlive.js-master/pdftex-1.40.11/". I'am not sure the solution is right or not, and I don't know if there is a better solution.

Hope that helps

@manuels @fzimmermann89