Using rustfmt in spacemacs on mac
I had some issues getting rustfmt to work in spacemacs on my mac. Here’s roughly how I got it working.
In particular, these are the most important steps:
- Confirm you’re using rustfmt-nightly
- Export LD_LIBRARY_PATH
- Use exec-path-from-shell in your spacemacs config
Confirm you’re using rustfmt-nightly
You can use rustup show to see whether you’re using the nightly version.
You can install rustfmt-nightly with
cargo install rustfmt-nightly --force
rustup run nightly rustfmt --help to confirm that your nightly version of rustfmt works.
For whatever reason, macs don’t like linking the LD_LIBRARY_PATH stuff by default. This causes problems for rustfmt.
export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH, and then try running
rustfmt --help to see if it worked.
If it doesn’t, then try also using
export DYLD_LIBRARY_PATH=$(rustc --print sysroot)/lib and running rustfmt again. If that doesn’t work, then I’m sorry as I didn’t have issues after that.
Assuming it does work, you now want to put those exports into your .bash_profile so they get loaded every time you start a shell.
Source your .bash_profile, and then confirm it works by running rustfmt in a new shell.
Use exec-path-from-shell in your spacemacs
Spacemacs won’t know how to load those exports by default. So we need to tell it to get those paths somehow.
You can use exec-path-from-shell to do just this. Put the following into your .spacemacs in the user-config section:
(require 'exec-path-from-shell) (exec-path-from-shell-initialize) ;; This is used for rustfmt (exec-path-from-shell-copy-env "LD_LIBRARY_PATH")
You might also need to add the DYLD_LIBRARY_PATH as well (I didn’t)
Now if you restart spacemacs, you should be able to use rustfmt in it.