updated to properly only restart zinc if it was freshly installed

build/mvn

@@ -43,12 +43,13 @@ install_mvn() {
 
 # Install zinc under the build/ folder
 install_zinc() {
-  ZINC_INSTALL_FLAG=1
+  local zinc_path="zinc-0.3.5.3/bin/zinc"
+  [ ! -f "${zinc_path}" ] && ZINC_INSTALL_FLAG=1
   install_app \
     "http://downloads.typesafe.com/zinc/0.3.5.3" \
     "zinc-0.3.5.3.tgz" \
-    "zinc-0.3.5.3/bin/zinc"
-  ZINC_BIN="${_DIR}/zinc-0.3.5.3/bin/zinc"
+    "${zinc_path}"
+  ZINC_BIN="${_DIR}/${ZINC_PATH}"
 }
 
 # Determine the Scala version from the root pom.xml file, set the Scala URL,
@@ -74,12 +75,9 @@ print(minidom.parse('${_DIR}/../pom.xml').getElementsByTagName('scala.version')[
 }
 
 # Determines if a given application is already installed. If not, will attempt
-# to install if the -f (forced install) flag was set from the command line
-# options.
-# Leverages the build/packages directory for package install files which
-# cater installation of a given application across various operating systems.
-# - Current supported operating systems are Linux, Solaris, BSD, and OSX
+# to install
 ## Arg1 - application name
+## Arg2 - Alternate path to local install under build/ dir
 check_and_install_app() {
   # create the local environment variable in uppercase
   local app_bin="`echo $1 | awk '{print toupper(\$0)}'`_BIN"
@@ -98,21 +96,21 @@ ZINC_PORT=${ZINC_PORT:-"3030"}
 
 # Check and install all applications necessary to build Spark
 check_and_install_app "mvn"
-check_and_install_app "zinc"
 
-# Check and download the proper version of Scala for the build
+# Install the proper version of Scala and Zinc for the build
+install_zinc
 install_scala
 
 # Reset the current working directory
 cd "${_DIR}/.."
 
 # Now that zinc is ensured to be installed, check its status and, if its
-# not running, start it
+# not running or just installed, start it
 if [ -n "${ZINC_INSTALL_FLAG}" -o -z "`${ZINC_BIN} -status`" ]; then
   ${ZINC_BIN} -shutdown
   ${ZINC_BIN} -start -port ${ZINC_PORT} \
     -scala-compiler "${SCALA_COMPILER}" \
-    -scala-library "${SCALA_LIBRARY}" &>/dev/null
+    -scala-library "${SCALA_LIBRARY}"
 fi
 
 # Last, call the `mvn` command as usual