=> Bootstrap dependency digest>=20010302: found digest-20160304 => Fetching V4.4.0.tar.gz => Total size: 1933037 bytes Certificate verification failed for /C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA 34374371912:error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed:/usr/src/crypto/openssl/ssl/s3_clnt.c:1269: fetch: https://github.com/wernerd/ZRTPCPP/archive/V4.4.0.tar.gz: Authentication error fetch: Unable to fetch expected file V4.4.0.tar.gz V4.4.0.tar.gz 0 B 0 Bps => Checksum SHA1 OK for libzrtpcpp/V4.4.0.tar.gz => Checksum RMD160 OK for libzrtpcpp/V4.4.0.tar.gz => Checksum SHA512 OK for libzrtpcpp/V4.4.0.tar.gz