urllib failed to download (reason: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed

[bin-mech]

How to fix following issue, thank you very much !
Downloading https://github.com/xianyi/OpenBLAS/archive/v0.2.13.tar.gz...
[ERROR] urllib failed to download (reason: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581)): https://github.com/xianyi/OpenBLAS/archive/v0.2.13.tar.gz
Downloading https://github.com/xianyi/OpenBLAS/archive/v0.2.13.tar.gz...
[ERROR] urllib failed to download (reason: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581)): https://github.com/xianyi/OpenBLAS/archive/v0.2.13.tar.gz
Downloading https://github.com/xianyi/OpenBLAS/archive/v0.2.13.tar.gz...
[ERROR] urllib failed to download (reason: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581)): https://github.com/xianyi/OpenBLAS/archive/v0.2.13.tar.gz
[CRITICAL] You may wish to check your Internet connection or the remote server

[vbraun]

Which operating system?

[bin-mech]

ubuntu 14.04

[bin-mech]

export SSL_CERT_DIR=/etc/ssl/certs
seems solving my problem.

[certik]

@bin-mech the other option is to use this PR: hashdist/hashdist#344, and the new -N option that it implements.