The original nix-repl repo seems to be licensed under the GPLv3, but this repo is LGPL v2.1. I don't believe it's possible to relicense contributions from various contributors without getting their explicit approval.
@edolstra Is there a record of contributors agreement to relicensing for the merging of nix-repl into this repo?

cc other nix-repl contributors (list taken from https://github.com/edolstra/nix-repl/graphs/contributors)
cc @solson @fkz @ehmry @olejorgenb @orbekk @mbbx6spp