Tmplt Wrote:Bookwyrm is currently licensed under the GPLv3+, mostly because pybind11 is as well. Will this cause trouble during packaging?

No. Any widely approved-of free license is fine. Any license on this list is 100% ok: https://opensource.org/licenses/alphabetical. The FSF's list is also good: https://www.gnu.org/licenses/license-list.en.html.

But some of the licenses on that list come with a comment saying they don't recommend their use (all of the nonfree ones, for instance. And the WTFPL).

So you have nothing to worry about.