=> Bootstrap dependency digest>=20010302: found digest-20160304
=> Fetching ppx_core-0.9.2.tar.gz
=> Total size: 44562 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/janestreet/ppx_core/archive/v0.9.2.tar.gz: Authentication error
fetch: Unable to fetch expected file ppx_core-0.9.2.tar.gz
ppx_core-0.9.2.tar.gz                                    0  B    0  Bps
=> Checksum SHA1 OK for ppx_core-0.9.2.tar.gz
=> Checksum RMD160 OK for ppx_core-0.9.2.tar.gz
=> Checksum SHA512 OK for ppx_core-0.9.2.tar.gz