I'm trying to implement a credential caching mechanism in git_cred_acquire_cb function. However, SSH session authentication does not report any error for libssh2 calls that return LIBSSH2_ERROR_PASSWORD_EXPIRED or LIBSSH2_ERROR_AUTHENTICATION_FAILED error codes (see _git_ssh_authenticate_session). The only exception is the ssh-agent authentication that sets error when failed. Failure to report auth errors makes impossible to identify if cached credentials where correct or not.