Re: configure script for GNU sed 4.8 generated by buggy unreleased Autoconf (was re: "configure" tries to execute what seems to be a shell command)

[Sidney Cadot]

Hi Zack,

> I'm curious how you came to notice it.

I’ve been running automated builds of several GNU packages under strace, to 
gain an understanding of package interdependencies (i.e., which configure/make 
scripts execute what commands). This popped up when I tried to automatically 
parse the strace-generated syscall logs.

(As an aside: I was surprised to see the number of processes that were started 
even when just doing a “./configure —help” (36 in all, including stuff like 
‘rm', ‘mkdir', ‘chown’, and ‘ln’). To someone like me who is not familiar with 
the inner workings of autoconf, this looks quite excessive for a command 
invocation that emits some help text to stdout.)

> I don't think there's anything more we can do in Autoconf, but I'm
> cc:ing the maintainer of GNU sed to let them know that they might want
> to spin a new release with a version of autoconf that doesn't have
> this bug.

The problem is not unique to sed, it was just one of the smallest packages to 
demonstrate it. Of the dozen or so packages I tested, sed-4.8, diffutils-3.7, 
and grep-3.4 showed this behavior, but there are probably others.

By your analysis it doesn’t seem to be a huge problem fortunately. I’m happy to 
hear it’s been fixed in the baseline version of autoconf that will be out soon..

Thanks for your prompt reply,

Sidney