hunk ./cabal-main-directory 1
-while [ $PWD != / ] ; do
-  if [ -e *.cabal ] ; then
-    echo $PWD
-    break
+while [ ! -e *.cabal ] ; do
+  OLDDIR=$PWD;
+  cd ..;
+  if [ $OLDDIR == $PWD ] ; then
+    exit 1 ;   # reached root node
hunk ./cabal-main-directory 7
-  cd ..
hunk ./cabal-main-directory 8
+echo $PWD