Resolution: Won't Fix
On a host that has curl built without OpenSSL, N1QL query throws following exception.
System.PlatformNotSupportedException: The libcurl library in use (7.29.0) and its SSL backend ("NSS/3.21 Basic ECC") do not support custom handling of certificates. A libcurl built with OpenSSL is required.
This is due to https://github.com/couchbase/couchbase-net-client/blob/master/Src/Couchbase/N1QL/QueryClient.cs#L393, which calls System.Net.Http.HttpClient.PostAsync that requires libcurl with OpenSSL.
Workaround is to upgrade libcurl to later than 7.29.0.
On CentOS, since 7.29.0 is the latest, download and install
with yum. Example is
'yum install libcurl-openssl-7.43.0-1.1.x86_64.rpm'
which will install a single file /opt/shibboleth/lib64/libcurl.so.4.3.0 and a symbolic link.
Then replace /usr/lib64/libcurl.so.4.3.0 with /opt/shibboleth/lib64/libcurl.so.4.3.0 or do whatever symbolic link that will invoke new libcurl.so.4.3.0