document TAP_DIAG and TAP_BUFFER environs

isaacs · isaacs · commit 60efe9538b20 · 2017-01-07T20:18:52.000-08:00
diff --git a/bin/usage.txt b/bin/usage.txt
@@ -173,6 +173,17 @@ Environment Variables:
                               running child tests so that their output
                               is parseable by the test harness.
 
+  TAP_DIAG                    Set to '1' to show diagnostics by
+                              default for passing tests.  Set to '0'
+                              to NOT show diagnostics by default for
+                              failing tests.  If not one of these two
+                              values, then diagnostics are printed by
+                              default for failing tests, and not for
+                              passing tests.
+
+  TAP_BUFFER                  Set to '1' to run subtests in buffered
+                              mode by default.
+
   _TAP_COVERAGE_              Reserved for internal use.
 
 Config Files:
