Use the -Z unpretty=hir flag to produce a human-readable representation of the HIR.
For cargo projects this can be done with cargo rustc -- -Z unpretty=hir.
This output is useful when you need to see at a glance how your code was desugared and transformed
during AST lowering.
For a full Debug dump of the data in the HIR, use the -Z unpretty=hir-tree flag.
This may be useful when you need to see the full structure of the HIR from the perspective of the
compiler.
If you are trying to correlate NodeIds or DefIds with source code, the
-Z unpretty=expanded,identified flag may be useful.
TODO: anything else? #1159