=> Bootstrap dependency digest>=20010302: found digest-20160304
=> Fetching nlopt-2.4.2.tar.gz
=> Total size: 2361992 bytes
ftp: Error retrieving file `404 Not Found'
fetch: Unable to fetch expected file nlopt-2.4.2.tar.gz
=> Checksum SHA1 OK for nlopt-2.4.2.tar.gz
=> Checksum RMD160 OK for nlopt-2.4.2.tar.gz