[tlbuild] How to compile BibTeX from source?

[Karl Berry]

Hi Henri - source/extra/bibtex is only there for convenience (of Oren
and me).  That's why it isn't buildable. It's not meant to be a full
standalone distribution and never will be, just bare sources for us to
play with.

The only way I have ever built bibtex is as part of web2c (nowadays,
TeX Live).

If you want to use a Pascal compiler, I wish you well, but have no
experience (since the days of Berkeley pc, anyway :).  --karl