vala: make vapigen suspectible to wrapping.

srcpkgs/vala/template

@@ -1,7 +1,7 @@
 # Template file for 'vala'
 pkgname=vala
 version=0.42.5
-revision=4
+revision=5
 build_style=gnu-configure
 configure_args="--disable-graphviz"
 hostmakedepends="flex libxslt pkg-config automake libtool"
@@ -28,6 +28,15 @@ pre_configure() {
 	autoreconf -fi
 }
 
+post_install() {
+	# remove the /usr/bin prefix from the vapigen variable
+	# so the package that use it fall into our wrapper.
+	# keep the binary versioned, we don't know the potential
+	# fallout from using the unversioned one
+	vsed -e 's|^vapigen=.*|vapigen=vapigen-0.42|g' \
+		 -i ${DESTDIR}/usr/lib/pkgconfig/vapigen-0.42.pc
+}
+
 libvala_package() {
 	short_desc+=" - vala shared library"
 	pkg_install() {