This is the output when I try to emerge blam-1.8.4_pre2 checking for i686-pc-linux-gnu-pkg-config... (cached) /usr/bin/pkg-config checking pkg-config is at least version 0.9.0... yes checking for BASE_DEPENDENCIES... configure: error: Package requirements (mono >= 1.1.17 gtk-sharp-2.0 >= 2.8.2 gconf-2.0 >= 2.4) were not met: Requested 'mono >= 1.1.17' but version of Mono is 1.1.13.8.1 Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. Alternatively, you may set the environment variables BASE_DEPENDENCIES_CFLAGS and BASE_DEPENDENCIES_LIBS to avoid the need to call pkg-config. See the pkg-config man page for more details. So I think that should be modified the required dependency.
Fixed in portage, thanks for the notification