Does not symlink modules with overlapping paths

[jgresty]

Suppose a go.mod contains:

require (
    repo/foo v1.0.0
    repo/foo/bar v1.0.0
)

then go mod will store the directory structure:

go
└── pkg
    └── mod
        └── repo
            ├── foo
            │   └── bar
            └── [email protected]

so that repo/foo v1.0.0 is installed under go/pkg/mod/repo/[email protected] to avoid conflicts.

However when gomod2nix creates the vendor-env derivation it seems to be only linking the longest path, in this case repo/foo/bar.

Discovered with go.opentelemetry.io/otel and related packages.