Re: rust: cargo build-system: how to handle libraries

[David Craven]

> Of course I meant Cargo.lock, not Cargo.toml ... so I know what I
> have to search for, and this makes it a bit easier than the
> previous search.

See cargo workspaces:
https://github.com/rust-lang/libc/blob/master/Cargo.toml
https://github.com/rust-lang/rfcs/blob/master/text/1525-cargo-workspace.md

It's a fairly new thing, you'll have to track down the relevant
commits in cargo and check if the cargo version we are using is new
enough and understand it's semantics and how it applies to the cargo
build system.

My recommendation to fix this issue is to not run the tests if there
isn't a Cargo.lock file, but this is likely not going to solve the
underlying cause in this case. You can also package version 0.2.16
which does not use workspaces.