Dear Maintainer, the version of curl in trixie 8.14.1-2+deb13u3 is missing https://github.com/curl/curl/commit/17f2a220a99db30bacd66df4df677dfb0a18b405 This means that any attempt to use private keys via OpenSSL engines (e.g. PKCS#11 via libengine-pkcs11-openssl) fails without a error message. Compared to bookworm, that's a regression. The version in trixie-backports 8.19.0-1~bpo13+1 contains the fix and works fine. Could you pick the fix for trixie as well? Thanks, Jan Lübbe