=> Bootstrap dependency digest>=20010302: found digest-20160304
=> Fetching xfrac310.zip
=> Total size: 1074760 bytes
Certificate verification failed for /C=US/O=Let's Encrypt/CN=Let's Encrypt Authority X3
34374371912:error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed:/usr/src/crypto/openssl/ssl/s3_clnt.c:1269:
fetch: https://fractint.org/ftp/current/linux/xfrac310.zip: Authentication error
fetch: Unable to fetch expected file xfrac310.zip
xfrac310.zip                                             0  B    0  Bps
=> Checksum SHA1 OK for xfrac310.zip
=> Checksum RMD160 OK for xfrac310.zip
=> Checksum SHA512 OK for xfrac310.zip