Some limitations:

(require "fennelview") – i.e. requiring the library distributed with the
language – does not work. I spoke with members of freenode's #fennel and
a FENNEL_PATH could be added. In a future package definition,
wrap-program would set that variable. In the meantime, this can be
worked around:

         fennel --add-fennel-path "$(guix build fennel )/share/?.fnl"

No native readline support. I have decided not to package
https://luarocks.org/modules/peterbillam/readline as fennel 0.2.1's use
of readline does not give more functionality than rlwrap.