Support for PREBUILT_ILLUMOS, and optional /tmp/debug.$$ output.

@@ -163,10 +163,14 @@
         shift
         tobuild=$*
         if [ -z "$tobuild" ] || [ "$tobuild" == "all" ]; then
                 batch_flag="-b"
                 for tgt in "${!fulltargets[@]}"; do
+                        # Uncomment the echo line if you want to see a
+                        # one-package-per-line status of what's building in
+                        # /tmp/debug.<PID>.
+                        # echo "Target = $tgt" >> /tmp/debug.$$
                         build $tgt
                 done
         else
                 for tgt in $tobuild; do
                         build $tgt