Re: [9fans] Re: configure misery

[Geoff Collyer <geoff@collyer.net>]

configure is undeniably convenient when it works; it's the times it
doesn't work that are a pain.  If the configure authors haven't seen
your particular variant system, configure is very likely to either
generate an incorrect configuration or blow up and refuse to run.  The
incorrect configuration isn't too bad; you can just edit config.h.
But when it refuses to run, you then get to wade into the `object
code' shell script, which is dense and complicated, and try to
persuade it to do the right thing and continue to run.  I find that
deleting large sections of configure often accomplish this.  If that
fails, compiling by hand may be easier than coaxing configure into
working.  And you get to do this for every program you try to import
that uses configure.

And some of the things that configure probes for just aren't worth
probing for.  Every ANSI/POSIX C implementation has to provide a
compiler under the name `c89'.  So why does configure still probe for
compiler names?  If you have a very old system and still don't have an
ANSI C implementation, you're going to have a very hard time importing
software in general and you probably ought to go get one (lcc and gcc
are just two that come to mind).  configure also tries to verify that
the compiler it has found generates .o files.  I know this isn't
required by the 1989 C standard and I doubt that POSIX requires it,
and indeed some ANSI compilers we know don't generate .o files.
Similarly, configure probes for the system include-file directory; why
does it care?  The whole process would work *better* if configure just
stopped checking for things like this.  After all, how many systems
have commands named `c89' that don't generate locally-appropriate
object files?

And cross-compilation would seem to be out of the question with
configure, unless configure runs itself remotely on the target and
drags the answers back.

I think one can live in the real world and still find configure to be
a larger problem than the one it claims to solve.