In Guix commit 7cb4440951fa3a91d48c63ac5be123636abfcf82. I found that ripgrep and fd will emit a `.crates.toml` file outside of FHS structure(at the root of profile).

For example, the .crates.toml file from fd looks like.

```
[v1]
"fd-find 8.1.1 (path+file:///tmp/guix-build-fd-8.1.1.drv-0/fd-find-8.1.1)" = ["fd"]
```

This file records the build directory, I think we'd better to exclude this to improve the determinisitc(If this file doesn't affect the functionality).

If we can't exclude it, it's better to place it in a proper place, if we leave it in the root of profile, .crates.toml from different rust apps will override each other.