fractal: add support for cross compilation

@Cogitri

srcpkgs/fractal/template

@@ -1,23 +1,25 @@
 # Template file for 'fractal'
 pkgname=fractal
 version=4.0.0
-revision=1
+revision=2
 build_style=meson
-hostmakedepends="rust cargo pkg-config glib-devel"
+build_helper="rust"
+hostmakedepends="cargo pkg-config glib-devel"
 makedepends="gtk+3-devel libglib-devel libressl-devel gstreamer1-devel
  cairo-devel gettext-devel gst-plugins-base1-devel gst-plugins-bad1-devel
  gtksourceview-devel pango-devel gspell-devel gmp-devel libsecret-devel
- libhandy-devel"
+ libhandy-devel rust-std"
 short_desc="Matrix Messaging Client for GNOME"
 maintainer="Cameron Nemo <camerontnorman@gmail.com>"
 license="GPL-3.0-or-later"
 homepage="https://wiki.gnome.org/Apps/Fractal"
 distfiles="https://gitlab.gnome.org/World/fractal/-/archive/$version/$pkgname-$version.tar.gz"
 checksum=f55b01dba5512abedd907d65bf1cd3a96243d81004152cd681ce7e306f777c2f
-nocross="Can't find rust std - seems to ignore RUSTFLAGS"
 
-pre_build() {
-	export GETTEXT_BIN_DIR=/usr/bin
-	export GETTEXT_LIB_DIR="${XBPS_CROSS_BASE}/usr/lib/gettext"
-	export GETTEXT_INCLUDE_DIR="${XBPS_CROSS_BASE}/usr/include"
-}
+if [ "$CROSS_BUILD" ]; then
+	pre_build() {
+		vsed -i scripts/cargo.sh \
+			-e 's/target\//&${RUST_TARGET}\//' \
+			-e '/CARGO_HOME/d'
+	}
+fi