Debuginfo level

src/compiler-debugging.md

@@ -46,9 +46,10 @@ stack backtrace:
   37: rustc_driver::run_compiler
 ```
 
-If you want line numbers for the stack trace, you can enable
-`debuginfo-level = 1` or `debuginfo-level = 2` in your config.toml and rebuild the
-compiler. Then the backtrace will look like this:
+If you want line numbers for the stack trace, you can enable `debug = true` in
+your config.toml and rebuild the compiler (`debuginfo-level = 1` will also add
+line numbers, but `debug = true` gives full debuginfo). Then the backtrace will 
+look like this:
 
 ```text
 stack backtrace:

src/how-to-build-and-run.md

@@ -28,17 +28,17 @@ settings (and possibly others, such as `llvm.ccache`):
 assertions = true
 
 [rust]
-# This enables some assertions, but more importantly it enables the `debug!`
-# logging macros that are essential for debugging `rustc`.
-debug-assertions = true
-
 # This will make your build more parallel; it costs a bit of runtime
 # performance perhaps (less inlining) but it's worth it.
 codegen-units = 0
 
-# I always enable full debuginfo, however the line debuginfo (which is a more important part
-# and enables e.g. line numbers in backtraces) is enabled by `debuginfo-level = 1` too.
-debuginfo-level = 2
+# This enables full debuginfo and debug assertions. The line debuginfo is also
+# enabled by `debuginfo-level = 1`. Full debuginfo is also enabled by
+# `debuginfo-level = 2`. Debug assertions can also be enabled with
+# `debug-assertions = true`. Note that `debug = true` will make your build
+# slower, so you may want to try individually enabling debuginfo and assertions
+# or enable only line debuginfo which is basically free.
+debug = true
 ```
 
 ### What is `x.py`?