Correctly set 'cargo fmt' It formats correctly but hx --health complains it cannot find the bin

[andreacfromtheapp]

Summary

Hi, thanks for helix. Just trying it out and I already love it. I can see myself using it as my main editor.

Now, I just wanted to point out that the correct formatter settings for Rust (cargo fmt) works with format on save but that hx --health complains about it. I suppose because the health check looks for a binary in a $PATH and cargo fmt is a sub binary (for lack of better word). The following settings work fine but for the --health check:

❯ head -12 ~/.config/helix/languages.toml
#### Rust START
[[language]]
name = "rust"
language-servers = ["rust-analyzer", "tailwindcss-ls", "harper-ls"]
formatter = { command = "cargo fmt", args = [""] }

[language-server.rust-analyzer.config.check]
command = "clippy"

[language-server.rust-analyzer.config.cargo]
features = "all"
##### Rust END

❯ hx --health rust
Configured language servers:
  ✓ rust-analyzer: /Users/andreacfromtheapp/.cargo/bin/rust-analyzer
  ✓ tailwindcss-ls: /Users/andreacfromtheapp/.local/state/fnm_multishells/2242_1752918305548/bin/tailwindcss-language-server
  ✓ harper-ls: /opt/homebrew/bin/harper-ls
Configured debug adapter:
  ✓ /opt/homebrew/opt/llvm/bin/lldb-dap
Configured formatter:
  ✘ 'cargo fmt' not found in $PATH
Tree-sitter parser: ✓
Highlight queries: ✓
Textobject queries: ✓
Indent queries: ✓

Reproduction Steps

1. Set Rust in languages.toml as follows:

#### Rust START
[[language]]
name = "rust"
language-servers = ["rust-analyzer", "tailwindcss-ls", "harper-ls"]
formatter = { command = "cargo fmt", args = [""] }

[language-server.rust-analyzer.config.check]
command = "clippy"

[language-server.rust-analyzer.config.cargo]
features = "all"
##### Rust END

2. edit any rust file and save. it just works.

I expected this to happen:

hx --health rust should correctly detect cargo fmt

Instead, this happened:

❯ hx --health rust
Configured language servers:
  ✓ rust-analyzer: /Users/andreacfromtheapp/.cargo/bin/rust-analyzer
  ✓ tailwindcss-ls: /Users/andreacfromtheapp/.local/state/fnm_multishells/2242_1752918305548/bin/tailwindcss-language-server
  ✓ harper-ls: /opt/homebrew/bin/harper-ls
Configured debug adapter:
  ✓ /opt/homebrew/opt/llvm/bin/lldb-dap
Configured formatter:
  ✘ 'cargo fmt' not found in $PATH
Tree-sitter parser: ✓
Highlight queries: ✓
Textobject queries: ✓
Indent queries: ✓

Helix log

no pertinent log found

Platform

macOS

Terminal Emulator

Ghostty 1.1.3

Installation Method

brew

Helix Version

helix 25.07.1 (a05c151)

[the-mikedavis]

The program is cargo and the first arg is fmt so you would specify the formatter as this instead:

formatter = { command = "cargo", args = ["fmt"] }

cargo-fmt does not support reading files from stdin and printing the formatted versions to stdout which is what formatter programs are expected to do. You should be able to delete that line since rust-analyzer should take care of formatting on write. If formatting is currently working even though the formatter program is marked as "not found in PATH" then rust-analyzer is already being used for formatting.

[andreacfromtheapp]

The program is cargo and the first arg is fmt so you would specify the formatter as this instead:

formatter = { command = "cargo", args = ["fmt"] }

I tried setting as you suggest and it doesn't work. all it does is delete the content of the source file.

[andreacfromtheapp]

however.... removing the line dos work, as you say. thanks :)

[andreacfromtheapp]

This issue led me to learn about rustfmt vs cargo fmt and that they are basically the same thing for different purposes.

What threw me off, is that hx --health rust formatter field shows None. Perhaps something to document or "change".

thank you again for helix and for your help!