Update pull-binary-libs.sh to cope with curl not installed

Author: VladUreche

pull-binary-libs.sh

@@ -2,6 +2,18 @@
 #
 # Script to pull binary artifacts for scala from the remote repository.
 
+# Avoid corrupting the jar cache in ~/.sbt and the ugly crash when curl is not installed 
+# This affects Linux systems mostly, because wget is the default download tool and curl
+# is not installed at all.
+curl --version &> /dev/null
+if [ $? -ne 0 ]
+then
+  echo ""
+  echo "Please install curl to download the jar files necessary for building Scala."
+  echo ""
+  exit 1
+fi
+
 . $(dirname $0)/tools/binary-repo-lib.sh
 
 # TODO - argument parsing...