--- a/gtk+.SlackBuild	2021-03-24 17:03:19.895738578 +0000
+++ b/gtk+.SlackBuild	2021-03-24 17:05:01.275136601 +0000
@@ -60,6 +60,12 @@
 elif [ "$ARCH" = "x86_64" ]; then
   SLKCFLAGS="-O2 -fPIC"
   LIBDIRSUFFIX="64"
+elif [ "$ARCH" = "aarch64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
+elif [ "$ARCH" = "riscv64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
 else
   SLKCFLAGS="-O2"
   LIBDIRSUFFIX=""
@@ -101,7 +107,9 @@
 zcat $CWD/gtk+-1.2.10-format.patch.gz | patch -p0 --verbose || exit 1
 
 # The original config.{guess,sub} do not work on x86_64 and some other $ARCH:
-cp -p /usr/share/libtool/build-aux/config.{guess,sub} .
+#cp -p /usr/share/libtool/build-aux/config.{guess,sub} .
+xzcat $CWD/config.guess.xz > config.guess || exit 1
+xzcat $CWD/config.sub.xz > config.sub || exit 1
 
 # Make sure ownerships and permissions are sane:
 chown -R root:root .