makepkg: hack around tee in run_package function

Piping the package function through tee to log the outut also
clears any variables set in the package function.  This is a
problem in split packages as package variable overrides are done
in the package function.  This is fixed by creating a node which
the output is piped through and duplicated using the tee function.

Signed-off-by: Allan McRae <allan@archlinux.org>

scripts/makepkg.sh.in

@@ -740,7 +740,16 @@ run_package() {
 			mv "$BUILDLOG" "$BUILDLOG.$i"
 		fi
 
-		package 2>&1 | tee "$BUILDLOG"; ret=${PIPESTATUS[0]}
+		# ensure overridden package variables suvrive tee with split packages
+		logpipe=$(mktemp -u "$startdir/logpipe.XXXXXXXX")
+		mknod "$logpipe" p
+		exec 3>&1
+		tee "$BUILDLOG" < "$logpipe" &
+		exec 1>"$logpipe" 2>"$logpipe"
+		package 2>&1 || ret=$?
+		sync
+		exec 1>&3 2>&3 3>&-
+		rm "$logpipe"
 	else
 		package 2>&1 || ret=$?
 	fi