Cargo error message when depending on binary crate should be better

[Boscop]

If one tries to depend on a binary crate the error message is currently "can't find crate" but it should be "can't depend on binary crates" or similar.

[dwijnand]

This doesn't error any more. For example depending on hexyl = "0.4.0" now just succeeds:

08:03:03 $ cargo b
    Updating crates.io index
  Downloaded hexyl v0.4.0
   Compiling t-cargo-dep-on-binary v0.1.0 (/s/t-cargo-dep-on-binary)

[epage]

From #7825, I'm assuming this will now warn about "no linkable targets". We need to confirm this is resolved

[weihanglo]

This has been improved with #9771. Now it looks like

    Updating crates.io index
  Downloaded term_size v0.3.2
  Downloaded ctrlc v3.4.0
  Downloaded hexyl v0.4.0
  Downloaded 3 crates (39.7 KB) in 1.09s
warning: x v0.1.0 (/projects/x) ignoring invalid dependency `hexyl` which is missing a lib target
    Finished dev [unoptimized + debuginfo] target(s) in 6.00s

Close as resolved.