fixup-redirects

diff --git a/stack.sh b/stack.sh
index ec13338..612cf73 100755
--- a/stack.sh
+++ b/stack.sh
@@ -388,6 +388,7 @@ if [[ -n "$LOGFILE" ]]; then
     # Set fd 3 to a copy of stdout. So we can set fd 1 without losing
     # stdout later.
     exec 3>&1
+    exec 4>&2
     if [[ "$VERBOSE" == "True" ]]; then
         # Set fd 1 and 2 to write the log file
         exec 1> >( $TOP_DIR/tools/outfilter.py -v -o "${LOGFILE}" ) 2>&1
@@ -409,6 +410,7 @@ else
     # Set fd 3 to a copy of stdout. So we can set fd 1 without losing
     # stdout later.
     exec 3>&1
+    exec 4>&2
     if [[ "$VERBOSE" != "True" ]]; then
         # Throw away stdout and stderr
         exec 1>/dev/null 2>&1
@@ -1505,6 +1507,6 @@ echo_summary "stack.sh completed in $SECONDS seconds."
 
 # Restore/close logging file descriptors
 exec 1>&3
-exec 2>&3
+exec 2>&4
 exec 3>&-
 exec 6>&-