=> Bootstrap dependency digest>=20010302: found digest-20160304 => Fetching img2eps-0.2.tar.gz => Total size: 404286 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://www.nih.at/img2eps/img2eps-0.2.tar.gz: Authentication error fetch: Unable to fetch expected file img2eps-0.2.tar.gz img2eps-0.2.tar.gz 0 B 0 Bps => Checksum SHA1 OK for img2eps-0.2.tar.gz => Checksum RMD160 OK for img2eps-0.2.tar.gz => Checksum SHA512 OK for img2eps-0.2.tar.gz