When adding the "tde" branch to the automated testing, I ran into build issues. I've fixed them for the "backend not enabled" case (see the latest commit in https://cgit.freedesktop.org/SyncEvolution/syncevolution/log/?h=for-master/tde: https://cgit.freedesktop.org/SyncEvolution/syncevolution/commit/?h=for-master/tde&id=e05817a4929873c72b8880f571b96e9ea7a4b786 But I'm wondering whether the untested "backend enabled" case really worked. To me it seemed that some includes were missing. I've changed that. EKO, can you test that branch and if further changes are needed, submit patches here against it?