https.Agent and client certificates, empty error object on wrong passphrase

[kyrrek]

We are using HTTPS with client certificates for some of the communications channels in our solution, and have a specific problem.
The certificates are stored in a PKCS12 store, and if we give the wrong passphrase as an option to https.Agent, the error object returned is empty. Do you think this is a user-related issue, or a problem with the implementation? We really would like to be able to log a specific error if something goes wrong, and to be able to pin-point the actual problem.