>>> Unpacking source...
>>> Unpacking nspluginwrapper-0.9.91.2.tar.bz2 to /var/tmp/portage/net-www/nspluginwrapper-0.9.91.2/work
>>> Source unpacked.
>>> Compiling source in /var/tmp/portage/net-www/nspluginwrapper-0.9.91.2/work/nspluginwrapper-0.9.91.2 ...
./configure --prefix=/usr --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --with-biarch --with-lib32=lib32 --with-lib64=lib64 --pkglibdir=/usr/lib64/nspluginwrapper --libdir=/usr/lib64 --build=x86_64-pc-linux-gnu
GTK+ 2.0 environment not found

!!! ERROR: net-www/nspluginwrapper-0.9.91.2 failed.
Call stack:
  ebuild.sh, line 1614:   Called dyn_compile
  ebuild.sh, line 971:   Called qa_call 'src_compile'
  environment, line 3295:   Called src_compile
  nspluginwrapper-0.9.91.2.ebuild, line 24:   Called econf '--with-biarch' '--with-lib32=lib32' '--with-lib64=lib64' '--pkglibdir=/usr/lib64/nspluginwrapper'
  ebuild.sh, line 577:   Called die

!!! 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/net-www/nspluginwrapper-0.9.91.2/temp/build.log'.