doc: write more about ENABLE_DEBUG
see
@@ -442,14 +442,20 @@ It is not recommended to use these options.
Build documentation with doxygen (API) and ronn (man pages).
+
#### Developer Options
-As developer you should enable `ENABLE_DEBUG` and `ENABLE_LOGGER`.
-By default no logging will take place, see [CODING](/doc/CODING.md)
-for information about logging.
+As developer you should enable `ENABLE_DEBUG` and `ENABLE_LOGGER`:
+- `ENABLE_DEBUG`:
+ - enables assertions
+ - adds RTLD_NODELETE so that debugger finds symbols even after dlclose
+- `ENABLE_LOGGER`:
+ enables logging
+ By default no logging will take place,
+ see [CODING](/doc/CODING.md) for how to get log messages.
+
+Continue reading [testing](/doc/TESTING.md) for more information about testing.
-Then continue reading [testing](/doc/TESTING.md) for options about
-testing.
#### `CMAKE_INSTALL_PREFIX`
