% echo -e '#!/bin/sh\necho user:s3cr3t' > /tmp/askpass
% chmod +x /tmp/askpass
% wget --use-askpass=/tmp/askpass https://debian.org
--2019-11-20 22:14:24-- https://user%3As3cr3t:*password*@debian.org/
^^^^^^^^^^^^^^^^^^^^^^^^
There seems to be a bug here, possibly related to the output of the askpass
script being HTML-encoded too early.
HTTP basic auth still works (though not on debian.org, but I've
tried it on other sites).