pmake: exec(mtree) failed (No such file or directory)
*** Error code 1

Stop.
pmake: stopped in /var/tmp/portage/freebsd-lib-6.2/work/include

!!! ERROR: sys-freebsd/freebsd-lib-6.2 failed.
Call stack:
  ebuild.sh, line 1539:   Called dyn_install
  ebuild.sh, line 1013:   Called src_install
  freebsd-lib-6.2.ebuild, line 197:   Called die

!!! Install failed
!!! If you need support, post the topmost build error, and the call stack if relevant.