Why No "Cargo Install" For Libraries?

JimLynchCodes · February 12, 2022, 7:22pm

I am coming from the world of node.js and npm where you can easily run "npm install blah" in an existing project to install the blah library. The cli tool figures out the latest version that will work, installs it, and automatically updates the package.json file.

When I just tried to run "cargo install dialogue" in a rust project I was kind of disappointed that cargo gave me this error:

error: there is nothing to install in `dialoguer v0.10.0`, because it has no binaries
`cargo install` is only for installing programs, and can't be used with libraries.
To use a library crate, add it as a dependency in a Cargo project instead.

Is there a reason why cargo purposely makes the user update cargo.toml by hand? Is there any flag or other command I can use to install a library easily similar to the npm way? Thanks!

RedDocMD · February 12, 2022, 7:24pm

There is a cargo sub-command for it called cargo edit. You can install it with cargo install cargo-edit. Then you can add packages like cargo add regex@0.1.41.

jdahlstrom · February 12, 2022, 7:45pm

cargo install is specifically for installing executables into your system (ie. somewhere along $PATH) so they can be run from the command line. It is not for adding dependencies to your projects.

kpreid · February 12, 2022, 7:56pm

And the cargo add command is going to be integrated into Cargo so it will always be available:

github.com/rust-lang/cargo

Add cargo-add (from cargo-edit) to cargo proper

opened 11:53AM - 28 May 18 UTC

killercup

A-new-subcommand T-cargo

Cargo as well as cargo-edit have gone a long way since #4 was opened. It might n…ow make sense to move (parts of) cargo-edit into cargo itself. Basically, we now have a format-preserving TOML library that -- at least for adding a dependency line -- work quite well (you can test this with `cargo install cargo-edit --vers 0.3.0-beta.1 -f`). Speaking with @matklad, I believe I now have a somewhat solid understanding of what needs to happen to add a new built-in cargo subcommand. One important realization was that cargo-install already contains some of the parts we need. Here are some steps to get started: 1. Create a `src/bin/cargo/commands/add.rs` (as duplicate of `install.rs` at first) 2. In `src/bin/cargo/commands/mod.rs`, add `add` to `builtin`/`builtin_exec`, and to the list of `mod`s 3. Create a `src/bin/cargo/ops/cargo_add.rs` (as duplicate of `cargo_install.rs` at first) One thing we should aim for though, is to now just copy-paste the whole of cargo-edit but to re-use as much of cargo's infrastructure as possible. For example, we should try to use cargo's way of querying the registry as well as its CLI args handling and output formatting. We can, for example, also use `args.workspace.current_manifest` to get the manifest and deal with workspace.

jeang3nie · February 12, 2022, 9:25pm

That's fantastic news!

kornel · February 12, 2022, 11:29pm

In Cargo, install means a different thing. It's closer to npm i -g and only for the .bin dir.

To "install" dependencies in a project, edit Cargo.toml files.

system · May 13, 2022, 11:30pm

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