=> Bootstrap dependency digest>=20010302: found digest-20160304 => Fetching crawl-0.4.tar.gz => Total size: 111084 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: http://monkey.org/~provos/crawl-0.4.tar.gz: Authentication error fetch: Unable to fetch expected file crawl-0.4.tar.gz crawl-0.4.tar.gz 0 B 0 Bps => Checksum SHA1 OK for crawl-0.4.tar.gz => Checksum RMD160 OK for crawl-0.4.tar.gz => Checksum SHA512 OK for crawl-0.4.tar.gz