You appear to have set $CFLAGS, perhaps you also need to tell GMP the
intended ABI, see "ABI and ISA" in the manual.
!!! Please attach the following file when seeking support:
!!! /var/tmp/portage/dev-libs/gmp-4.2.2/work/gmp-4.2.2/config.log
*
* ERROR: dev-libs/gmp-4.2.2 failed.
* Call stack:
* ebuild.sh, line 49: Called src_compile
* environment, line 2618: Called econf 'src_compile' 'src_compile' '--localstatedir=/var/state/gmp' '--disable-mpfr'
* ebuild.sh, line 513: Called die
* The specific snippet of code:
* die "econf failed"
* The die message:
* econf failed
*
* If you need support, post the topmost build error, and the call stack if relevant.
* A complete build log is located at '/var/tmp/portage/dev-libs/gmp-4.2.2/temp/build.log'.
* The ebuild environment file is located at '/var/tmp/portage/dev-libs/gmp-4.2.2/temp/environment'.
*
* Messages for package dev-libs/gmp-4.2.2:
*
* ERROR: dev-libs/gmp-4.2.2 failed.
* Call stack:
* ebuild.sh, line 49: Called src_compile
* environment, line 2618: Called econf 'src_compile' 'src_compile' '--localstatedir=/var/state/gmp' '--disable-mpfr'
* ebuild.sh, line 513: Called die
* The specific snippet of code:
* die "econf failed"
* The die message:
* econf failed
*
* If you need support, post the topmost build error, and the call stack if relevant.
* A complete build log is located at '/var/tmp/portage/dev-libs/gmp-4.2.2/temp/build.log'.
* The ebuild environment file is located at '/var/tmp/portage/dev-libs/gmp-4.2.2/temp/environment'.
*
* Regenerating GNU info directory index...
* Processed 78 info files.