After updating coreutils you may encounter a problem using touch. This problem often manifests itself as a loop while trying to update other packages:

 *   Touching gcc/cstamp-h.in
 *   touch: setting times of `gcc/cstamp-h.in': No such file or directory
 *   make: *** [gcc/cstamp-h.in] Error 1
 *   Touching gcc/cstamp-h.in
 *   touch: setting times of `gcc/cstamp-h.in': No such file or directory
 *   make: *** [gcc/cstamp-h.in] Error 1
...

or a one-off event that breaks the merge:

touch: setting times of `config.h.in': No such file or directory
make: *** [config.h.in] Error 1
emake failed
 * ERROR: sys-process/psmisc-22.12 failed (compile phase):
 *   (no error message)
 * 
 * Call stack:
 *     ebuild.sh, line  56:  Called src_compile
 *   environment, line 2663:  Called die
 * The specific snippet of code:
 *       emake || die
 * 
 * If you need support, post the output of 'emerge --info =sys-process/psmisc-22.12',
 * the complete build log and the output of 'emerge -pqv =sys-process/psmisc-22.12'.
 * The complete build log is located at '/var/tmp/portage/sys-process/psmisc-22.12/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/sys-process/psmisc-22.12/temp/environment'.
 * S: '/var/tmp/portage/sys-process/psmisc-22.12/work/psmisc-22.12'

>>> Failed to emerge sys-process/psmisc-22.12,

This problem occurs on systems running kernels older than 2.6.22, where futimesat was introduced. This pops up a lot on my older Gentoo VMs for obvious reasons (wouldn't it be nice if we could have an up-to-date stable xen-sources package one day?).

You have four options:

Upgrade your kernel - this is the ideal solution but in an ideal world we all live forever and make too much money.

Disable sandbox - sandbox is intended to soften poorly written scripts. simply add -sandbox to your FEATURES variable. Not a big fan of this solution.

Replace touch with busybox's implementation - this is a neat trick but I have encountered problems using bb's touch in place of coreutils and the next time you update the symlink may get wiped out.

# rm /bin/touch && ln -s /bin/bb /bin/touch

Mask versions of coreutils newer than 8.5 - this is the ideologically correct way to take care of things if upgrading the kernel is not in your cards today.

# echo ">=sys-apps/coreutils-8.6" >> /etc/portage/package.mask

It's important that you remember to remove the mask once you do. Funnily enough, if you have already installed coreutils-8.6+ emerging 8.5 will fail due to the broken touch, in this case you may wish to temporarily use one of the other solutions to get it installed:

checking for struct utmpx.ut_exit.e_termination... yes
checking for struct utmp.ut_exit.e_termination... yes
checking for stdlib.h... (cached) yes
checking for GNU libc compatible realloc... yes
checking for working re_compile_pattern... yes
checking whether rename honors trailing slash on destination... touch: setting times of `conftest.f': No such file or directory
configure: error: cannot create temporary files

!!! Please attach the following file when seeking support:
!!! /var/tmp/portage/sys-apps/coreutils-8.5/work/coreutils-8.5/config.log
 * ERROR: sys-apps/coreutils-8.5 failed (compile phase):
 *   econf failed
 * 
 * Call stack:
 *     ebuild.sh, line   56:  Called src_compile
 *   environment, line 2495:  Called econf '--with-packager=Gentoo' '--with-packager-version=8.5 (p1)' '--with-packager-bug-reports=http://bugs.gentoo.org/' '--enable-install-program=arch' '--enable-no-install-program=groups,hostname,kill,su,uptime' '--enable-largefile' '--disable-libcap' '--enable-nls' '--enable-acl' '--disable-xattr' '--without-gmp'
 *     ebuild.sh, line  557:  Called die
 * The specific snippet of code:
 *                      die "econf failed"
 * 
 * If you need support, post the output of 'emerge --info =sys-apps/coreutils-8.5',
 * the complete build log and the output of 'emerge -pqv =sys-apps/coreutils-8.5'.
 * The complete build log is located at '/var/tmp/portage/sys-apps/coreutils-8.5/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/sys-apps/coreutils-8.5/temp/environment'.
 * S: '/var/tmp/portage/sys-apps/coreutils-8.5/work/coreutils-8.5'

>>> Failed to emerge sys-apps/coreutils-8.5