upgpkg: 4.18.0-3 Overall rework of the PKGBUILD

Context: https://archlinux.org/todo/general-xfce-packages-rework/

- Update URL (point to upstream doc webpage for the package)
- Use SPDX identifier for the license
- Switch to a more transparent source (git sources)
- Add nvchecker integration (.nvchecker.toml)

.SRCINFO

 pkgbase = xfwm4
 	pkgdesc = Xfce's window manager
 	pkgver = 4.18.0
-	pkgrel = 2
+	pkgrel = 3
 	url = https://docs.xfce.org/xfce/xfwm4/start
 	arch = x86_64
 	groups = xfce4
-	license = GPL2
+	license = GPL-2.0-or-later
+	makedepends = git
 	makedepends = intltool
+	makedepends = xfce4-dev-tools
 	depends = libxfce4ui
 	depends = xfconf
 	depends = libwnck3
 	depends = libepoxy
 	depends = libxpresent
 	depends = hicolor-icon-theme
-	source = https://archive.xfce.org/src/xfce/xfwm4/4.18/xfwm4-4.18.0.tar.bz2
-	sha256sums = 92cd1b889bb25cb4bc06c1c6736c238d96e79c1e706b9f77fad0a89d6e5fc13f
+	source = git+https://gitlab.xfce.org/xfce/xfwm4.git#tag=xfwm4-4.18.0
+	sha256sums = a9b2efae4a6ff8a9100b5ca174deb045a3d1787689098802217cda6a8dc20779
 
 pkgname = xfwm4

.nvchecker.toml

+[xfwm4]
+source = "git"
+git = "https://gitlab.xfce.org/xfce/xfwm4.git"
+prefix = "xfwm4-"
+exclude_regex = '.*pre.*|xfwm4-4\.[12][13579]\.[0-9]+'

PKGBUILD

 # Maintainer: Evangelos Foutras <foutrelis@archlinux.org>
+# Maintainer: Robin Candau <antiz@archlinux.org>
 # Contributor: tobias <tobias funnychar archlinux.org>
 
 pkgname=xfwm4
 pkgver=4.18.0
-pkgrel=2
+pkgrel=3
 pkgdesc="Xfce's window manager"
 arch=('x86_64')
 url="https://docs.xfce.org/xfce/xfwm4/start"
-license=('GPL2')
+license=('GPL-2.0-or-later')
 groups=('xfce4')
 depends=('libxfce4ui' 'xfconf' 'libwnck3' 'libepoxy' 'libxpresent'
          'hicolor-icon-theme')
-makedepends=('intltool')
-source=(https://archive.xfce.org/src/xfce/$pkgname/${pkgver%.*}/$pkgname-$pkgver.tar.bz2)
-sha256sums=('92cd1b889bb25cb4bc06c1c6736c238d96e79c1e706b9f77fad0a89d6e5fc13f')
+makedepends=('git' 'intltool' 'xfce4-dev-tools')
+source=("git+https://gitlab.xfce.org/xfce/xfwm4.git#tag=$pkgname-$pkgver")
+sha256sums=('a9b2efae4a6ff8a9100b5ca174deb045a3d1787689098802217cda6a8dc20779')
 
-build() {
-  cd $pkgname-$pkgver
-
-  ./configure \
+prepare() {
+  cd $pkgname
+  ./autogen.sh \
     --prefix=/usr \
     --sysconfdir=/etc \
     --localstatedir=/var \
@@ -27,11 +27,15 @@ build() {
     --enable-compositor \
     --enable-xsync \
     --disable-debug
+}
+
+build() {
+  cd $pkgname
   make
 }
 
 package() {
-  cd $pkgname-$pkgver
+  cd $pkgname
   make DESTDIR="$pkgdir" install
 }