emerge --emptytree system
Calculating system dependencies ...done!
>>> emerge (1 of 98) sys-devel/patch-2.5.9-r1 to /
>>> checksums files   ;-) patch-2.5.9.ebuild
>>> checksums files   ;-) patch-2.5.9-r1.ebuild
>>> checksums files   ;-) files/digest-patch-2.5.9
>>> checksums files   ;-) files/patch-2.5.9-cr-stripping.patch
>>> checksums files   ;-) files/digest-patch-2.5.9-r1
>>> checksums src_uri ;-) patch-2.5.9.tar.gz
>>> Unpacking source...
>>> Unpacking patch-2.5.9.tar.gz to /var/tmp/portage/patch-2.5.9-r1/work
 * Applying patch-2.5.9-cr-stripping.patch ...                            [ ok ]>>> Source unpacked.
>>> Compiling source in /var/tmp/portage/patch-2.5.9-r1/work/patch-2.5.9 ...
./configure --prefix=/usr --host=i686-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --build=i686-pc-linux-gnu
checking for i686-pc-linux-gnu-gcc... i686-pc-linux-gnu-gcc
checking for C compiler default output... configure: error: C compiler cannot create executables
See `config.log' for more details.

!!! Please attach the following file when filing a report to bugs.gentoo.org:
!!! /var/tmp/portage/patch-2.5.9-r1/work/patch-2.5.9/config.log

!!! ERROR: sys-devel/patch-2.5.9-r1 failed.
Call stack:
  ebuild.sh, line 1894:   Called dyn_compile
  ebuild.sh, line 941:   Called src_compile
  patch-2.5.9-r1.ebuild, line 33:   Called econf

!!! econf failed
!!! If you need support, post the topmost build error, and the call stack if relevant.