annotate tests/artifacts/PURPOSE @ 51238:633408a0f2e2

revlog: always use a Rust index for REVLOGv1 if rustext is present

We are about to change classes such as `rustext.AncestorsIterator` to
take a Rust index, hence we cannot have the option not to use the Rust
index.

Note: this can be refined depending on whether we want to keep this
option or not. We will have to make two versions of `AncestorsIterator`
and its sibling to support REVLOGV2 and CHANGELOGv2 anyway.

Meanwhile, this is the simplest change to make the tests pass.

This directory is meant to cache artifacts useful for tests (such as bundle).

Those artifacts need to be cached because they are slow to regenerate on each
test but too large to be tracked within the repository. They are not expected
to change between each run and can be cached.

The `./scripts/` contains code to generate the artifact while the `cache`
directory contains resulting artifact.