=> Bootstrap dependency digest>=20010302: found digest-20190127
=> Fetching gromacs-4.5.5.tar.gz
=> Total size: 10398178 bytes
ftp: Error retrieving file `503 Backend unavailable, connection timeout'
fetch: Unable to fetch expected file gromacs-4.5.5.tar.gz
=> Checksum SHA1 OK for gromacs-4.5.5.tar.gz
=> Checksum RMD160 OK for gromacs-4.5.5.tar.gz
=> Checksum SHA512 OK for gromacs-4.5.5.tar.gz