rust-lldb not available on Linux

[Luthaf]

Trying to run rust-lldb gives me the error: infinite recursion detected: the command may not exist for this toolchain error.

rust-llbd is effectively missing in .multirust/toolchains/stable/bin but it could be installed there, as lldb is available on Linux. (I got mine from the epel repo, but some people can also have it installed from sources).

Is it an issue for multirust or for the main rust repo ?

[brson]

This could have a better error than just blindly recursing. I don't intend to remove the proxy binary and think Rust should distribute rust-gdb and rust-lldb unconditionally.

[Luthaf]

think Rust should distribute rust-gdb and rust-lldb unconditionally.

I am in favour of that too.

[Luthaf]

Dup of #335