message: Add a section for `--test_arg=--logtostderr --test_output=all`
diff: @@ -62,6 +62,12 @@ bazel test base:util_test --config oss_linux -c dbg
  * `util_test` is defined in `base/BUILD.bazel`.
  +The `--test_arg=--logtostderr --test_output=all` flags shows the output of
  +unitests to stderr.
  +
  +```
  +bazel test base:util_test --config oss_linux --test_arg=--logtostderr --test_output=all
  +```
  ### Build Mozc on other Linux environment
  