talanin-vm ~ # emerge dev-php/pecl-memcache
--- Invalid atom in /etc/portage/package.mask: ;<=dev-php/pecl-memcache-2.2.7

 * IMPORTANT: 8 news items need reading for repository 'gentoo'.
 * Use eselect news to read news items.

Calculating dependencies -

!!! Problem resolving dependencies for dev-php/pecl-memcache                                                                                                                                                                               ... done!

!!! The ebuild selected to satisfy "dev-php/pecl-memcache" has unmet requirements.
- dev-php/pecl-memcache-3.0.8::gentoo USE="session" ABI_X86="64" PHP_TARGETS="-php5-3 -php5-4 -php5-5"

  The following REQUIRED_USE flag constraints are unsatisfied:
    any-of ( php_targets_php5-5 php_targets_php5-3 php_targets_php5-4 )