Files on host vs build

[Peter Eisentraut]

With all this talk about files on host and build systems, I have another
issue on my mind, and it is Autoconf itself that is the culprit (amongst
countless other packages).

The Autoconf configure script looks for Perl and substitutes the found
program into autoscan.pl.  Similarly, it takes the value of SHELL that it
gets in puts it into various *.sh programs.  Isn't that a violation of the
host vs build principle?  The Perl interpreter on the host machine could
be somewhere else.  The shell might be different.  With Shell and Perl
this might not be such a large problem, but other packages do this with
Tcl, Python, ipcs, echo(!), etc.

The purist would answer "You need to check for XXX at run time."  Should
this be done here?

(How this comes back to AC_CHECK_FILE:  It can be perfectly valid to check
for a file on the build system, if you use it right.  It can also be
perfectly *invalid* to check for a program on the build system, if you use
it wrong.  Autoconf shouldn't lay traps if it doesn't have all the
details.)

-- 
Peter Eisentraut      address@hidden       http://yi.org/peter-e/