clara repo is unable to read and import the private key because in the version of GPG on Scibian9 (>=2.1) they removed the secret keyring and let only gpg-agent has the control of the private part of key as explained here : https://www.gnupg.org/faq/whats-new-in-2.1.html#nosecring.
These modifications has a major impact on clara repo key and clara repo init, without a public/private key policy the initialization of repos or checking the keys give errors
clara repo is unable to read and import the private key because in the version of GPG on Scibian9 (>=2.1) they removed the secret keyring and let only gpg-agent has the control of the private part of key as explained here : https://www.gnupg.org/faq/whats-new-in-2.1.html#nosecring.
These modifications has a major impact on clara repo key and clara repo init, without a public/private key policy the initialization of repos or checking the keys give errors