None of these appear to be working... Edit to see the ways and means it fails.
language: lang-sql, no indent on Prettify comment
Select * from Foo where Foo.bar == "baz"
language: sql, no indent on Prettify comment
Select * from Foo where Foo.bar == "baz"
language: lang-sql, Prettify comment indented
<!-- language: lang-sql -->
Select * from Foo where Foo.bar == "baz"
language: sql, Prettify comment indented
<!-- language: sql -->
Select * from Foo where Foo.bar == "baz"