Mention some useful debugging options

diff --git a/README.md b/README.md
index 17811a2468927418aa4b8608aaa902515a4b961c..b49ba8409950c3e7fff1e007701a506a28a28c0f 100644 (file)
--- a/README.md
+++ b/README.md
@@ -35,7 +35,14 @@ anyRequest <|> anyResponse
 ```
 
 Try out the example tests in the `example` directory with `cabal test`.
-For more examples check the [Wiki](https://github.com/bubba/lsp-test/wiki/Introduction)
+For more examples check the [Wiki](https://github.com/bubba/lsp-test/wiki/Introduction).
+
+Whilst writing your tests you may want to debug them to see what's going wrong.
+You can set the `logMessages` and `logStdErr` options in `SessionConfig` to see what the server is up to.
+There are also corresponding environment variables so you can turn them on from the command line:
+```
+LSP_TEST_LOG_MESSAGES=1 cabal test
+```
 
 ## Developing
 The tests for lsp-test use a dummy server found in `test/dummy-server/`.