24363750 setting COMPILER=gcc with setup.py.mk doesn't affect all parts of the build
# When verifying a signature made from a subkey, ensure that the cross
# certification "back signature" on the subkey is present and valid.
# This protects against a subtle attack against subkeys that can sign.
# Defaults to --no-require-cross-certification. However for new
# installations it should be enabled.
require-cross-certification
keyserver hkp://keys.gnupg.net
keyserver-options honor-http-proxy auto-key-retrieve