Previously, if the prefer-index feature was enabled, crates-index
was used to read cache entries to fix features for crates.
However, crates-index can be a problematic dependency since it
requires git2 regardless of whether you use the git index or not
Using with-crates-index preserves the old behavior to just use
crates-index, however, prefer-index now allows users to implement
their own Index implementation if they would like leaving the choice of
git/http/etc up to the calling code
Previously, if the
prefer-indexfeature was enabled,crates-indexwas used to read cache entries to fix features for crates.However,
crates-indexcan be a problematic dependency since it requires git2 regardless of whether you use the git index or notUsing
with-crates-indexpreserves the old behavior to just usecrates-index, however,prefer-indexnow allows users to implement their own Index implementation if they would like leaving the choice of git/http/etc up to the calling code