doc/testing.md

*** 386,395 ****
--- 386,402 ----
  To run these tests correctly, additional parameters for the correct docker image are
  required on Ubuntu 18.04 by using `JAVA_OPTIONS`.
  
      $ make test TEST="jtreg:test/hotspot/jtreg/containers/docker" JTREG="JAVA_OPTIONS=-Djdk.test.docker.image.name=ubuntu -Djdk.test.docker.image.version=latest"
  
+ ### Non-English locale just for Linux
+ 
+ If your locale is non-English and when you "make test", it will appear some fail caused by the locale that non-English.
+ Then you can try to solve this problem by setting LANG before "make test".
+ 
+     $ export LANG="en_US"
+ 
  ---
  # Override some definitions in the global css file that are not optimal for
  # this document.
  header-includes:
   - '<style type="text/css">pre, code, tt { color: #1d6ae5; }</style>'