Re: "has changed since the previous run"

[Ralf Wildenhues]

* DJ Delorie wrote on Thu, Feb 01, 2007 at 03:25:36AM CET:
> 
> > Do you think that is feasible for GCC?  I know it far too little to
> > be able to judge.
> 
> No, sorry.  In gcc, binutils, gdb, newlib, et al; there is a toplevel
> configure and Makefile.  Configure programatically determines which of
> the available source directories will participate in the build, and
> creates a suitable Makefile.  The Makefile calls the sub-configures in
> turn.  They share config.cache, because it saves a lot of time.
> 
> So, yes, configure is getting called a lot, from different modules, at
> different times.

Would you please point me to one bug report where the issue actually was
only changed whitespace in the precious variables, or, even better, show
me how to reproduce the issue you observe (with a combined, up to date
tree)?

I found these bug reports only (and some others), but none fit the issue
you reported:
<http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18222>   fixed
<http://gcc.gnu.org/ml/gcc/2004-01/msg02101.html>     genuine build bug
<http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25470>
  non-whitespace difference in precious variable; plus build system bug

Here's what I tried so far, without a bug, on i686-pc-linux-gnu:

 CFLAGS='  -Dfoobar  -Dfoobaz="a"  ' \
 ../combined/configure --disable-multilib --enable-languages=c,c++,objc 
 make
 find ../combined -name configure | xargs touch
 make

Presumably your failure is triggered by some other rebuild mechanism.

Thanks,
Ralf