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

@@ -34,11 +34,17 @@
 # this going forward.
 VER=1.0.5.11
 # Default to building tip, but site.sh can force a specific commit checkout.
 COMMIT=$KVM_ROLLBACK
 SRC_REPO=https://github.com/joyent/illumos-kvm.git
-KERNEL_SOURCE=/code/omnios-$RELVER/illumos-omnios
+if [ -d ${PREBUILT_ILLUMOS:-/dev/null} ]; then
+    logmsg "Using pre-built Illumos at $PREBUILT_ILLUMOS (may need to wait...)"
+    wait_for_prebuilt
+    KERNEL_SOURCE=$PREBUILT_ILLUMOS
+else
+    KERNEL_SOURCE=/code/omnios-$RELVER/illumos-omnios
+fi
 PROTO_AREA=$KERNEL_SOURCE/proto/root_i386
 PATCHDIR=patches.$PROG
 PKG=driver/virtualization/kvm
 SUMMARY="placeholder; reset below"
 DESC="$SUMMARY"

@@ -106,11 +112,17 @@
 # Next, the utilities (they follow the kernel module version)
 PROG=illumos-kvm-cmd
 # Default to building tip, but site.sh can force a specific commit checkout.
 COMMIT=$KVM_CMD_ROLLBACK
 SRC_REPO=https://github.com/joyent/illumos-kvm-cmd.git
-KERNEL_SOURCE=/code/omnios-$RELVER/illumos-omnios
+if [ -d $PREBUILT_ILLUMOS:-/dev/null ]; then
+    logmsg "Using pre-built Illumos at $PREBUILT_ILLUMOS (may need to wait...)"
+    wait_for_prebuilt
+    KERNEL_SOURCE=$PREBUILT_ILLUMOS
+else
+    KERNEL_SOURCE=/code/omnios-$RELVER/illumos-omnios
+fi
 KVM_DIR=$TMPDIR/illumos-kvm-$VER
 PATCHDIR=patches.$PROG
 PKG=system/kvm
 
 # Reset a couple of important things