[tlbuild] Failure to 'Build -disable-all-pkgs --enable-web2c'

[Andreas Scherer]

Dear all,

As of commit 70984 or 70985 TeX Live fails to build.

Locally, 'Build -disable-all-pkgs --enable-web2c' stops with error message

checking for  options needed to detect all undeclared functions... 
cannot detect
configure: error: in '/opt/github/Extern/texlive-source/Work/texk/web2c':
configure: error: cannot make  report undeclared builtins
See 'config.log' for more details
=== configuring in web2c failed
make[2]: *** [Makefile:909: recurse] Error 1
make[2]: Leaving directory '/opt/github/Extern/texlive-source/Work/texk'
make[1]: *** [Makefile:480: all-recursive] Error 1
make[1]: Leaving directory '/opt/github/Extern/texlive-source/Work/texk'
make: *** [Makefile:574: all-recursive] Error 1
+ echo 2
done (exit status 2) Sun Apr 21 11:21:20 CEST 2024

and Github Actions fail for almost all systems (see 
https://github.com/TeX-Live/texlive-source/actions/runs/8745653899 for 
latest details).

Looking forward to a fix. Thanks.

Andreas