There are multiple issues lurking here.
The Rust language support is in git gdb. The next gdb release (7.12) will have it. This support provides a number of features, perhaps primarily Rust expression parsing.
Rust also ships a rust-gdb script. This script runs gdb with some parameters to ensure that gdb can load some Rust-specific pretty-printers, written in Python. These provide a nicer debugging experience, and work with more versions of gdb than just 7.12, but don’t address all the things the built-in support addresses.
However, my recollection is that qtcreator doesn’t use the normal pretty-printing approach, in favor of its own. So, it doesn’t benefit from the things that rust-gdb supplies. (This was certainly true in the past, but I don’t follow qtcreator, so perhaps they’ve changed this – in any case I’d recommend asking in a qtcreator forum.)
