diff --git a/doc/developer-notes.md b/doc/developer-notes.md
--- a/doc/developer-notes.md
+++ b/doc/developer-notes.md
@@ -126,6 +126,30 @@
 The Qt code routes qDebug() output to debug.log under category "qt": run with -debug=qt
 to see it.
 
+**running and debugging tests**
+
+Unit tests are run via `make check`
+For running functional tests, see `/test/README.md`
+
+Simple example of debugging unit tests with GDB on Linux:
+```
+cd /build/src/test
+gdb test_bitcoin
+break interpreter.cpp:295  # No path is necessary, just the file name and line number
+run
+# GDB hits the breakpoint
+p/x opcode  # print the value of the variable (in this case, opcode) in hex
+c           # continue
+```
+
+Simple example of debugging unit tests with LLDB (OSX or Linux):
+```
+cd /build/src/test
+lldb -- test_bitcoin
+break set --file interpreter.cpp --line 295
+run
+```
+
 **testnet and regtest modes**
 
 Run with the -testnet option to run with "play bitcoins" on the test network, if you