emerge rep-gtk失败

本来是想安装sawfish的, 但由于sawfish依赖于rep-gtk, 系统自动先emerge rep-gtk, 但是rep-gtk怎么也emerge不了. 我从源代码试着手工编译, 可以./configure,但make时出错, 具体错误和emerge的时候一样:

(.......省略.........)
libtool: compile: unable to infer tagged configuration
libtool: compile: specify a tag with `--tag'
make: *** [rep-gtk.lo] Error 1
make: *** Waiting for unfinished jobs....
libtool: compile: unable to infer tagged configuration
libtool: compile: specify a tag with `--tag'
make: *** [rep-types.lo] Error 1

!!! ERROR: x11-libs/rep-gtk-0.18-r1 failed.
!!! Function src_compile, Line 48, Exitcode 2
!!! (no error message)
!!! If you need support, post the topmost build error, NOT this status message.


请问如何解决?