glibmm: glib-compile-schemas is required during the build.

component/glibmm/buildout.cfg

@@ -17,7 +17,7 @@ pkg_config_depends = ${glib:location}/lib/pkgconfig:${libsigc:location}/lib/pkgc
 configure-options =
   --disable-documentation
 environment =
-  PATH=${perl:location}/bin:${pkgconfig:location}/bin:${xz-utils:location}/bin:%(PATH)s
+  PATH=${perl:location}/bin:${pkgconfig:location}/bin:${xz-utils:location}/bin:${glib:location}/bin:%(PATH)s
   PKG_CONFIG_PATH=${:pkg_config_depends}
   CPPFLAGS=-I${gettext:location}/include
   LDFLAGS=-L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib