=> Bootstrap dependency digest>=20010302: found digest-20160304
=> Fetching cffi-1.8.3.tar.gz
=> Total size: 403766 bytes
ftp: Error retrieving file `404 Not Found'
fetch: Unable to fetch expected file cffi-1.8.3.tar.gz
=> Checksum SHA1 OK for cffi-1.8.3.tar.gz
=> Checksum RMD160 OK for cffi-1.8.3.tar.gz
=> Checksum SHA512 OK for cffi-1.8.3.tar.gz