extra/cantor to 18.04.2-3

extra/cantor/PKGBUILD

@@ -8,7 +8,7 @@
 
 pkgname=cantor
 pkgver=18.04.2
-pkgrel=2
+pkgrel=3
 pkgdesc="KDE Frontend to Mathematical Software"
 url="https://kde.org/applications/education/cantor/"
 arch=(x86_64)
@@ -23,14 +23,19 @@ optdepends=('maxima: Maxima backend'
             'python: Python 3 backend'
 	    'python2: Python 2 backend'
             'sagemath: SageMath backend')
-source=("https://download.kde.org/stable/applications/$pkgver/src/$pkgname-$pkgver.tar.xz"{,.sig})
+source=("https://download.kde.org/stable/applications/$pkgver/src/$pkgname-$pkgver.tar.xz"{,.sig}
+        cantor-sagemath.patch::"https://cgit.kde.org/cantor.git/patch/?id=7e4d0819")
 sha256sums=('aab96ae512c3ddfaaf288ca0531b685c689a40a31222326441501b9a18bc320d'
-            'SKIP')
+            'SKIP'
+            '5b5275ae4cee20af865fe861ae07da976608913372ceb031b6bf70653fc2d21b')
 validpgpkeys=(CA262C6C83DE4D2FB28A332A3A6A4DB839EAA6D7  # Albert Astals Cid <aacid@kde.org>
               F23275E4BF10AFC1DF6914A6DBD2CE893E2D1C87) # Christoph Feck <cfeck@kde.org>
 
 prepare() {
   mkdir -p build
+
+  cd $pkgname-$pkgver
+  patch -p1 -i ../cantor-sagemath.patch # Fix sagemath backend
 }
 
 build() {