Parallelization of shell scripts for 'configure' etc.

[Paul Eggert]

In many Gnu projects, the 'configure' script is the biggest barrier to 
building because it takes soooo long to run. Is there some way that we 
could improve its performance without completely reengineering it, by 
improving Bash so that it can parallelize 'configure' scripts?

For ideas about this, please see PaSh-JIT:

Kallas K, Mustafa T, Bielak J, Karnikis D, Dang THY, Greenberg M, 
Vasilakis N. Practically correct, just-in-time shell script 
parallelization. Proc OSDI 22. July 2022. 
https://nikos.vasilak.is/p/pash:osdi:2022.pdf

I've wanted something like this for *years* (I assigned a simpler 
version to my undergraduates but of course it was too much to expect 
them to implement it) and I hope some sort of parallelization like this 
can get into production with Bash at some point (or some other shell if 
Bash can't use this idea).