tlrepo provides ThreadLocalRepo, a convenient way to share a
git2::Repository object between threads.
A standard git2::Repository object does not support sharing among threads
without some form of synchronization. tlrepo::ThreadLocalRepo provides a
convenient way to reopen the same repository on each thread, caching the opened
repository thread-locally for reuse.
You can create a ThreadLocalRepo by calling ThreadLocalRepo::new, or by
using the extension trait tlrepo::RepositoryExt to call .thread_local() on
an existing git2::Repository. You can share the ThreadLocalRepo across
threads, calling .get() to get a git2::Repository object to work with.