--- a/PKGBUILD	2018-03-21 18:08:08.138446567 +0100
+++ b/PKGBUILD	2018-03-21 18:22:01.229401254 +0100
@@ -17,7 +17,7 @@ md5sums=('SKIP')
 build() {
   cd "${srcdir}/${pkgname}-dev"
   make configure
-  export OPTIMIZER="-march=${CARCH/_/-} -O1"
+  export OPTIMIZER="-march=rv64gc -mabi=lp64d -O1"
   export DEBUG=-DNDEBUG
   ./configure --prefix=/usr --sbindir=/usr/bin --enable-readline
   make