Update stellarium-25.3.recipe (#13006)

* Stellarium 25.3: fix compiling with clang-20

sci-astronomy/stellarium/stellarium-25.3.recipe

@@ -5,7 +5,7 @@ binoculars or a telescope."
 HOMEPAGE="https://stellarium.org"
 COPYRIGHT="2000-2025 Stellarium Developers"
 LICENSE="GNU GPL v2"
-REVISION="2"
+REVISION="3"
 SOURCE_URI="https://github.com/Stellarium/stellarium/releases/download/v$portVersion/stellarium-$portVersion.tar.bz2"
 CHECKSUM_SHA256="b98a0bf6fd4cb45cc8885f049fd44371227d399a7901de171897b33938de4158"
 ADDITIONAL_FILES="stellarium.rdef.in"
@@ -62,9 +62,10 @@ BUILD_REQUIRES="
 	devel:libz$secondaryArchSuffix
 	"
 BUILD_PREREQUIRES="
-	llvm20
+	llvm20$secondaryArchSuffix
 	cmd:cmake
-	cmd:clang++
+	cmd:clang >= 20
+	cmd:clang++ >= 20
 	cmd:gcc$secondaryArchSuffix
 	cmd:make
 	cmd:lld >= 20
@@ -75,6 +76,9 @@ BUILD_PREREQUIRES="
 
 BUILD()
 {
+	export CC="/bin/clang"
+	export CXX="/bin/clang++"
+
 	mkdir -p build
 	cd build
 	cmake .. \