--- configure.orig	2017-12-12 20:06:03 UTC
+++ configure
@@ -267,16 +267,16 @@ fi
 # Auto-determine available backends
 if [ -z "$BACKENDS" ]; then
 	echo -n "Checking for supported backends..             "
-	BACKENDS="$($MAKE get_available_backends ${PKG_CONFIG:+PKG_CONFIG="$PKG_CONFIG"} | awk '/^BACKENDS:/ {print substr($0, 11);}')"
+	BACKENDS="$($MAKE get_available_backends ${PKG_CONFIG:+PKG_CONFIG="$PKG_CONFIG"} | awk '/^BACKENDS:/ {print substr($0, 11);}') "
 	echo "${BACKENDS:-(none)}"
 fi
 
 # Disable explicitly disabled and enable explicitly enabled backends
 for BACKEND in ${DISABLED_BACKENDS}; do
-	BACKENDS="${BACKENDS//${BACKEND} /}"
+	BACKENDS="${BACKENDS/${BACKEND}/}"
 done
 for BACKEND in ${ENFORCED_BACKENDS}; do
-	BACKENDS="${BACKEND} ${BACKENDS//${BACKEND} /}"
+	BACKENDS="${BACKEND} ${BACKENDS/${BACKEND} /}"
 done
 
 echo "Building with backends:                       ${BACKENDS:-(none)}"