I had to add the Open Software License to guix/licenses.scm. Debian
does not think of it as a Free Software license, but I think it's OK
with GNU.
The page at<https://www.gnu.org/licenses/license-list.html#OSL>
contains says it’s free but mentions worrisome details:
Recent versions of the Open Software License have a term which
requires distributors to try to obtain explicit assent to the
license. This means that distributing OSL software on ordinary FTP
sites, sending patches to ordinary mailing lists, or storing the
software in an ordinary version control system, is arguably a
violation of the license and would subject you to possible
termination of the license. [...]
We’re not distributing it, just distributing the build recipes.
However, would it be a violation to distribute pre-built binaries on
Hydra? Could you check that?