readme on osmo-trx and address sanitizer

Change-Id: I6fc9469ddb148651286cde3b0ce70913f99a7a0d
diff --git a/README b/README
index 28103a8..9533d89 100644
--- a/README
+++ b/README
@@ -130,3 +130,9 @@
 === src/*
 
 Find other useful scripts in src/, see src/README.
+
+
+=== Troubleshooting
+
+When using sanitize.opts, osmo-trx is not built with the address sanitizer
+enabled. Linking a sanitizer-enabled libosmocore will not work.