build: if there's no recent git tag, don't spew error messages

share/genbuild.sh

@@ -22,7 +22,7 @@ if [ -e "$(which git 2>/dev/null)" -a "$(git rev-parse --is-inside-work-tree 2>/
 
     # if latest commit is tagged and not dirty, then override using the tag name
     RAWDESC=$(git describe --abbrev=0 2>/dev/null)
-    if [ "$(git rev-parse HEAD)" = "$(git rev-list -1 $RAWDESC)" ]; then
+    if [ "$(git rev-parse HEAD)" = "$(git rev-list -1 $RAWDESC 2>/dev/null)" ]; then
         git diff-index --quiet HEAD -- && DESC=$RAWDESC
     fi