Ncdump (from netCDF4): I/O failure, curl error, SSL connect error

I am having trouble with the issue described here:

I have recently begun using Anaconda Pro. Am on Windows and working from my employer’s secure network. I succeeded with installing the ‘token’ utility, and authenticating my token.

At first I was getting SSL errors for commands such as “conda update conda”-- and also when using the python “requests” package (within my conda env called “EQ”) to retrieve data from servers such as https://coastwatch.pfeg.noaa.gov/erddap/tabledap.

I downloaded my certificate chain as a single file, appended it at the end of the cacert.pem file in my envs/EQ/Lib/site-packages/certifi folder, and configured conda with ssl_verify to use that file. Then the above SSL errors went away.

However, as shown in this screengrab, when I try to use ncdump I get errors:

(This happens when I am at work on our secure network, but it does NOT happen when I am at home on my (less secure) home network.)

Based on the discussion at github (see above link), it seems to be a certificate issue.

Any suggestions? Thanks in advance.

dear Daniel_Codiga.

Thank you for your contribution to the anaconda community.

This problem is also a problem with “certifi”.

Once, downgrade netCDF from 1.6.0 to netCDF 1.5.7
It looks like the issue is resolved.

Currently, “certifi” has been upgraded to 2022.9.24, so installing that may solve the problem.

Best regards.

Thank you for the suggestion.
I have certifi 2022.9.24 now.
I pinned netCDF4 to 1.5.7 and I still get the error (same as when using 1.6.1 of netCDF4:

  • schannel: CertGetCertificateChain trust error CERT_TRUST_REVOCATION_STATUS_UNKNOWN
  • Closing connection 1
    Error:curl error: SSL peer certificate or SSH remote key was not OK
    curl error details:
    Warning:oc_open: Could not read url
    C:\Users\codiga_d\Anaconda3\envs\EQ\Library\bin\ncdump.exe: http://psl.noaa.gov/thredds/dodsC/Datasets/NARR/monolevel/uwnd.10m.2000.nc: NetCDF: I/O failure

Note that I am not getting SSL errors when downloading packages, nor when accessing external websites using python ‘requests’ package. Only when using ncdump.

Do you have any other ideas?

dear Daniel_Codiga.

Thank you for your detailed reply.
It seems that this problem was not related to netCDF4.

Upon closer inspection, it’s an error related to curl.
For example:

https://www.simplified.guide/curl/skip-ssl-verification

In other words, the cause is that curl is not making an SSH connection correctly.

Sorry for the old topic, but I think the following sites will also be helpful.

Best regards.

Thank you.
I’m not seeing a solution at any of those sites.