=> Bootstrap dependency digest>=20211023: found digest-20220214
=> Fetching racket-6.12-src.tgz
=> Total size: 22271046 bytes
ftp: Error retrieving file `503 Backend unavailable, connection timeout'
fetch: Unable to fetch expected file racket-6.12-src.tgz
=> Checksum BLAKE2s OK for racket-6.12-src.tgz
=> Checksum SHA512 OK for racket-6.12-src.tgz