⚠️ This issue is filed on behalf of a user of the client libraries, full context is here GoogleCloudPlatform/python-docs-samples#1284 (comment)

What version of gRPC and what language are you using?

Python 2.7.15 with OpenSSL 1.0.2o 27 Mar 2018

What operating system (Linux, Windows, …) and version?

macOS

What runtime / compiler are you using (e.g. python version or version of gcc)

Unsure

What did you do?

The user attempted to run the sample here, but this does not appear unique to this sample.

What did you expect to see?

The sample work. :)

What did you see instead?

E0503 12:02:25.491373000 140735530255168 ssl_transport_security.cc:1063] Handshake failed with fatal error SSL_ERROR_SSL: error:1000007d:SSL routines:OPENSSL_internal:CERTIFICATE_VERIFY_FAILED

This appears to happen consistently.