emerge -pqv '=net-libs/gnutls-3.3.4-r1::gentoo'
!!! Found 2 make.conf files, using both '/etc/make.conf' and '/etc/portage/make.conf'
[ebuild     U ] net-libs/gnutls-3.3.4-r1 [3.2.12.1] USE="crywrap cxx nls zlib -dane -doc -examples -guile -pkcs11 -static-libs {-test}" ABI_X86="(64%*) -32% (-x32)" LINGUAS="en -cs -de -fi -fr -it -ms -nl -pl -sv -uk -vi -zh_CN" 

!!! The following installed packages are masked:
- virtual/python-argparse-1::gentoo (masked by: package.mask)
/usr/portage/profiles/package.mask:
# Michał Górny <mgorny@gentoo.org> (6 Jul 2014)
# (on behalf of python@gentoo.org)
# The modules provided by those virtuals are built-in in all currently
# supported Python implementations. If your ebuild depends on either
# of them, please just remove the dependency. Removal in 30 days.

- dev-db/firebird-2.5.2.26540.0::gentoo (masked by: package.mask)
/etc/portage/package.mask:
#>=dev-db/firebird-2.1.3.8185.0-r1

For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.