Debugging failures on x86_64-darwin17 of travis-ci

https://travis-ci.org/ruby/ruby/jobs/553346285

.travis.yml

@@ -374,9 +374,9 @@ before_script:
   - "> config.status"
   - "> .rbconfig.time"
   - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
-  - make touch-unicode-files
-  - make -s $JOBS $UPDATE_UNICODE up
-  - make -s $JOBS srcs
+  - date; make touch-unicode-files
+  - date; make -s $JOBS $UPDATE_UNICODE up
+  - date; make -s $JOBS srcs
   - rm -f config.status Makefile rbconfig.rb .rbconfig.time
   - |-
     if [ -d ~/config_2nd ]; then