Is there a way to skip some submodules?

[BusyJay]

Currently, cargo will populate all git submodule automatically and recursively. But sometimes not all submodules are needed, populate those unneeded modules (specially some large git repos) are just a waste of time. So is there a way to tell cargo to skip those submodules?

[alexcrichton]

Unfortunately we don't currently have a way of saying "exclude this submodule", but I could imagine interpreting the exclude key for this! (I don't think we do that today)

[dtolnay]

I noticed this for syn – syn-0.11.11.crate is 62k but .cargo/git/checkouts/syn-6f4912dca572d3ab is 2.8 gigs.

[BusyJay]

After #4837 is merged, it will be slower to add large repository with a lot of optional submodules as dependency.

[whereistejas]

Is using exclude still the recommended way to ignore git submodules?

[dtolnay]

The recommended way is to not have submodules I believe. See dtolnay/syn#183. Cargo fetches all submodules as part of checking out the repo, and reads the Cargo.toml after checking out the repo, so an exclude key in Cargo.toml wouldn't currently affect the submodule behavior.

#4247 (comment) proposes cloning the repo without submodules first, reading exclude from Cargo.toml, and fetching only submodules that are not excluded. As far as I know that is not implemented in Cargo which is why this issues remains open.