Rust is very stable as far as I'm concerned. 
My comments were about the Jetbrains IDEs only.
Thanks for mentioning GDB. That made me try it again, and it seems to be a big improvement in some cases. Unfortunately, the tests are much slower to execute with that toolchain: almost 4 times slower than LLDB. I have yet to determine what is slower and why.
Also, some libraries fail to compile.