depends_lib-append is not working

[lomion@…]

When trying to build a variant with additional dependencies it does not pick up depends_lib-append. There is already a dependency for the port, which is picked up. It picks up the patchfile fine. Example is below

depends_lib lib:libX11.a:XFree86

variant lesstif {

depends_lib-append lib:libUil:lesstif

patchfiles-append patch-Makefile.macosx.lesstif

}