Ability to test against registry dependencies, instead of path dependencies

[barakugav]

Problem

I have a monorepo with multiple Rust crates that depends on one another with both a path and version dependency. An example for a line in Cargo.toml:

my_crate_dep = {path = "../my_crate_dep", version="1.0.0"}

The behaviour of cargo to ignore the version during development and ignore the path during publish or package is amazing! When I run cargo package the crate it built with my_crate_dep from crates.io, and not my local dependency.
I would also like to cargo test with my_crate_dep from crates.io rather than local, in addition to the build.

Proposed Solution

One of the following will provide what I need:

• Add a flag to cargo test indicating to ignore path/git dependencies, maybe along the lines of --force-published-deps.
• Add a flag to cargo package to run tests

Notes

Actually I think such flags can be useful in many sub commands of cargo, maybe we should consider a wide option

[epage]

I've brought up a similar idea for cargo hack at taiki-e/cargo-hack#216.

I've also wondered about the ability to do cargo test --manifest-path foo.crate

The big challenge is when the registry versions of the packages are insufficient. maybe #10948 combined with -Zminimal-versions would make it so we could have all of the .crate files but only use when when absolutely necessary. Callers would still need a way to make them available. The way cargo packages verify step is doing it is internal-only