README.md: explain how to run a specific test from a specific file

https://bugzilla.gnome.org/show_bug.cgi?id=793190

diff --git a/README.md b/README.md
index 46f9e05..0719aca 100644 (file)
--- a/README.md
+++ b/README.md
@@ -103,12 +103,18 @@ To run all the tests of a specific component:
 meson test -C build --suite gst-plugins-base
 ```
 
-Or to run a specific test:
+Or to run a specific test file:
 
 ```
 meson test -C build/ --suite gstreamer gst_gstbuffer
 ```
 
+Run a specific test from a specific test file:
+
+```
+GST_CHECKS=test_subbuffer meson test -C build/ --suite gstreamer gst_gstbuffer
+```
+
 ## Add information about GStreamer development environment in your prompt line
 
 ### Bash prompt