should canonicalize the path?

```rust
Ok(
required_packages.into_iter()
.filter(|pkg| !available_packages.contains(pkg) && !PathBuf::from(pkg.access_package_name()).exists())
.collect()
)
```

Start by examining the package filtering expression shown in the issue, especially the PathBuf::from(pkg.access_package_name()).exists() check. Determine whether canonicalization is required for the intended package lookup and identify the relevant tests or entry point before changing behavior. Done means the expected path forms are handled and the behavior is covered by tests.

Written by the indexing model from the issue text.