Calculating dependencies... done!
>>> Emerging (1 of 1) sci-mathematics/scilab-2.7-r3 to /
>>> checking ebuild checksums ;-)
>>> checking auxfile checksums ;-)
>>> checking miscfile checksums ;-)
>>> checking scilab-2.7.src.tar.gz ;-)
>>> checking patch_browsehelp.tar.gz ;-)
which: no scilab in (/usr/local/sbin:/sbin:/usr/sbin:/usr/lib/portage/bin:/usr/local/bin:/bin:/usr/bin:/opt/bin:/usr/i686-pc-linux-gnu/gcc-bin/4.1.1:/usr/i686-pc-linux-gnu/gcc-bin/4.1.1:/usr/qt/3/bin)
which: no g77 in (/usr/local/sbin:/sbin:/usr/sbin:/usr/lib/portage/bin:/usr/local/bin:/bin:/usr/bin:/opt/bin:/usr/i686-pc-linux-gnu/gcc-bin/4.1.1:/usr/i686-pc-linux-gnu/gcc-bin/4.1.1:/usr/qt/3/bin)
 * No fortran compiler found on the system!
 * Please add fortran to your USE flags and reemerge gcc!

!!! ERROR: sci-mathematics/scilab-2.7-r3 failed.
Call stack:
  ebuild.sh, line 1555:   Called dyn_setup
  ebuild.sh, line 668:   Called pkg_setup
  scilab-2.7-r3.ebuild, line 41:   Called die

!!! (no error message)
!!! If you need support, post the topmost build error, and the call stack if relevant.