==> Validating source files with sha512sums...
txtorcon-20.0.0.tar.gz ... Passed
txtorcon-20.0.0.tar.gz.asc ... Skipped
==> Verifying source file signatures with gpg...
txtorcon-20.0.0.tar.gz ... FAILED (unknown public key C2602803128069A7)
==> ERROR: One or more PGP signatures could not be verified!
Error: Failed to build python-txtorcon