There is a port of git-cvs for OpenBSD. Run pkg_add git-cvs to install the
package.
To install git-cvs from source, ensure that you have a recent version of Simon Schubert's rcsparse library installed and then run setup.py:
sudo ./setup.py install
Clone a local CVS repository into a Git repository.
git cvs clone /cvs/src
This will parse all RCS files, generate changesets and import those changesets
into Git. Some metadata will be stored in .git/cvsgit.db and is required for
further incremental runs.
Update the Git repository with recent changesets from CVS.
git cvs pull
The CVSROOT for this command is the same as when the repository was cloned
initially. You can change the CVS repository location by modifying the
cvs.source option with git-config(1).
Git, on purpose, does not manage the mtime of checked out files in order to allow make(1) and similar tools to figure out which files must be rebuilt after switching branches. cvs sets the mtime to the repository mtime whenever checkout/update creates a new file, but not if the file already exists.