annotate tests/artifacts/PURPOSE @ 47305:33e7508b0ae9

hg-cpython: fix new occuring TypeError

dd339191f2dc introduced a minor refactoring of error types that highlighted
a fragile error creation mechanism that was in place in the Rust `MixedIndex`.

`PyErr::from_instance` also accepts a Python class, as long as it's an
`Exception` class. Before the aforementioned commit, we never ran into a case
where this duck-typing mechanism failed. We rectify this behavior by doing the
instantiation ourselves.

Differential Revision: https://phab.mercurial-scm.org/D10764

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.