pharo6: Minor fixes and cleanups

pkgs/development/pharo/launcher/default.nix

@@ -37,7 +37,7 @@ stdenv.mkDerivation rec {
 
     cat > $prefix/bin/${executable-name} <<EOF
     #!${bash}/bin/bash
-    exec ${pharo}/bin/pharo $prefix/share/pharo-launcher/pharo-launcher.image
+    exec "${pharo}/bin/pharo" $prefix/share/pharo-launcher/pharo-launcher.image
     EOF
     chmod +x $prefix/bin/${executable-name}
   '';
@@ -51,7 +51,7 @@ stdenv.mkDerivation rec {
      secs=5
      echo -n "Running headless Pharo for $secs seconds to check for a crash... "
      timeout $secs \
-       ${pharo}/bin/pharo -nodisplay PharoLauncher.image --no-quit eval 'true'
+       "${pharo}/bin/pharo" -nodisplay PharoLauncher.image --no-quit eval 'true'
      test "$?" == 124 && echo "ok")
   '';