diff --git a/HACKING b/HACKING
index 256e8aeb84..f9f838109c 100644
--- a/HACKING
+++ b/HACKING
@@ -123,6 +123,11 @@ VIR_TEST_DEBUG may provide larger amounts of information:
   VIR_TEST_DEBUG=1 make check    (or)
   VIR_TEST_DEBUG=2 make check
 
+When debugging failures during development, it is possible to focus in on just
+the failing subtests by using TESTS and VIR_TEST_RANGE:
+
+  make check VIR_TEST_DEBUG=1 VIR_TEST_RANGE=3-5 TESTS=qemuxml2argvtest
+
 Also, individual tests can be run from inside the "tests/" directory, like:
 
   ./qemuxml2xmltest
diff --git a/docs/hacking.html.in b/docs/hacking.html.in
index 0892b731af..543c77e180 100644
--- a/docs/hacking.html.in
+++ b/docs/hacking.html.in
@@ -141,6 +141,17 @@
   VIR_TEST_DEBUG=1 make check    (or)
   VIR_TEST_DEBUG=2 make check
 </pre>
+
+        <p>
+          When debugging failures during development, it is possible
+          to focus in on just the failing subtests by using TESTS and
+          VIR_TEST_RANGE:
+        </p>
+
+<pre>
+  make check VIR_TEST_DEBUG=1 VIR_TEST_RANGE=3-5 TESTS=qemuxml2argvtest
+</pre>
+
         <p>
           Also, individual tests can be run from inside the <code>tests/</code>
           directory, like: