>>> Source unpacked.
>>> Compiling source in /var/tmp/portage/sys-fs/mdadm-2.6.1/work/mdadm-2.6.1 ...
i686-pc-linux-gnu-gcc -Wall -march=pentium4 -O2 -pipe -fomit-frame-pointer -DSendmail=\""/usr/sbin/sendmail -t"\" -DCONFFILE=\"/etc/mdadm.conf\" -DCONFFILE2=\"/etc/mdadm/mdadm.conf\"   -c -o mdadm.o mdadm.c
/bin/sh: i686-pc-linux-gnu-gcc: command not found
make: *** [mdadm.o] Error 127

!!! ERROR: sys-fs/mdadm-2.6.1 failed.
Call stack:
  ebuild.sh, line 1614:   Called dyn_compile
  ebuild.sh, line 971:   Called qa_call 'src_compile'
  environment, line 3270:   Called src_compile
  mdadm-2.6.1.ebuild, line 29:   Called die

!!! emake 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/sys-fs/mdadm-2.6.1/temp/build.log'.