Closed
Description
Compiling libcore with -g leads to the following error:
error: internal compiler error: Type metadata for ty::t '&[core::fmt::rt::Piece<>]' is already in the TypeMap!
This is due to the vec slice in question occurring multiple times along a type reference chain and the code path for vec slices doesn't take that possibility into account. This is also a potential problem for other kinds of types, e.g. fixed length vector types or function types. For regular pointer types this is already handled correctly.