Am Samstag, 26. Januar 2013 schrieb Ludovic Courtès:
> You’ve created a circular dependency between ‘python’ and ‘compression’.
> 
> The fix is to arrange so that there’s no circular dependency.  The
> easiest way to achieve that is to move the package in question to its
> own module.

Okay, thanks! I realised after a few hours of debugging, that to execute 
the tests for the library zziplib, I also needed zip to create test data on 
the fly; so I added zip and unzip (and zziplib) in their own file.

Now I have problems with zziplib and pkg-config during the configuration of 
texlive. I have pkg-config and zziplib as inputs. But configure fails at

if $PKG_CONFIG zziplib --atleast-version=0.12; then
  ZZIPLIB_INCLUDES=`$PKG_CONFIG zziplib --cflags`
  ZZIPLIB_LIBS=`$PKG_CONFIG zziplib --libs`
elif test "x$need_zziplib:$with_system_zziplib" = xyes:yes; then
  as_fn_error $? "did not find zziplib-0.12 or better" "$LINENO" 5
fi

(while previous similar lines for other programs succeed). When I install 
the two guix packages by hand and execute the test in a terminal, it 
succeeds. Do you have any idea what could be happening?

Andreas