rust-analyzer takes too much time to load a project

[karagenc]

I'm using rust-analyzer version 2021-06-14 stable with Visual Studio Code. I have rust-analyzer plugin installed (the default official rust plugin is not installed).

When i open a project with Visual Studio Code, rust-analyzer takes too much time to initialize. Especially if the project is big and has a lot of dependencies it takes approximately 1 minute for intellisense to be enabled.

These 2 steps take the most time:

• Fetching metadata
• Indexing

I like rust-analyzer. It is a great LFS but i wish there was a cache or something because whenever i open a project i wait for a minute (sometimes a few minutes) for the intellisense.

[flodiebold]

Duplicate of #1650 / #4712, unless you have a specific project where indexing takes abnormally long.

[lnicola]

Also, "fetching metadata" means it's updating the cargo registry, which can take quite a while but is usually called by cargo itself.

[karagenc]

Sorry for duplicate issue. I'm new to Rust and i want to write an API server. But web frameworks (warp, rocket, gotham, actix) have a lot of dependencies. Try creating a simple web server with one of these frameworks and you'll see that rust-analyzer takes more than 30 seconds to initialize.

Indexing takes too much time.

Is it a problem related to my system? Or is it common for rust-analyzer to take too much time to index such a large set of dependencies?

Also fetching metadata take a while too. Does it fetch data from a server? Is this related to my internet connection?

Other than that, rust-analyzer is awesome. Thank you for your efforts!

[lnicola]

We need to run cargo metadata ("Fetching metadata") when loading the project, which can cause cargo to update its crate index (presumably if it's the first time you're compiling a project, or if the project is using a crate version that's not available locally). This is a git clone, but I've seen it take a couple of minutes.

We also run cargo check for diagnostics, proc macros and build scripts. You can disable all of these, but they happen in the background. "Indexing" is rust-analyzer itself.