Add build dependencies

Makefile

@@ -120,7 +120,7 @@ publish-ppa: ppa
 	dput ppa:yuezk/globalprotect-openconnect ../*.changes
 
 # Generate RPM sepc file
-rpm-spec:
+init-rpm:
 	rm -rf .build/rpm
 	mkdir -p .build/rpm
 
@@ -135,7 +135,7 @@ rpm-spec:
 	sed -i "s/@DATE@/$(shell LC_ALL=en.US date -u "+%a %b %e %T %Z %Y")/g" .build/rpm/globalprotect-openconnect.changes
 
 # Ensure ../globalprotect-openconnect-*.tar.gz exists.
-rpm: rpm-spec
+rpm: init-rpm
 	if [ ! -f ../$(PKG).tar.gz ]; then \
 		echo "Missing ../$(PKG).tar.gz"; \
 		exit 1; \
@@ -156,4 +156,20 @@ rpm: rpm-spec
 		cp $(HOME)/rpmbuild/SRPMS/$(PKG_NAME)*.rpm .build/rpm; \
 	fi
 
-pkgbuild:
+init-pkgbuild:
+	rm -rf .build/pkgbuild
+	mkdir -p .build/pkgbuild
+
+	if [ ! -f ../$(PKG).tar.gz ]; then \
+		echo "Missing ../$(PKG).tar.gz"; \
+		exit 1; \
+	fi
+	cp ../$(PKG).tar.gz .build/pkgbuild
+
+	cp packaging/pkgbuild/PKGBUILD.in .build/pkgbuild/PKGBUILD
+	sed -i "s/@PKG_NAME@/$(PKG_NAME)/g" .build/pkgbuild/PKGBUILD
+	sed -i "s/@VERSION@/$(VERSION)/g" .build/pkgbuild/PKGBUILD
+	sed -i "s/@REVISION@/$(REVISION)/g" .build/pkgbuild/PKGBUILD
+
+pkgbuild: init-pkgbuild
+	cd .build/pkgbuild && makepkg -s --noconfirm