Good news! I successfully could build hydra and xhydra (= hydra-gtk) within debian/trixie and of course including libsmbclient-dev.
It is working fine and I also could build a package of it. Sadly, something went wrong when building the package, as hydra-gtk is not in the package somehow (but it should!). I believe, this is my fault, as I am very few experienced with the debian package build process. Thus I am sure, I forgot so,ething or did something wrong. If someone would like to take a look at, I will be happy to upload my results, but these are about 5 MB . Please drop me a note, where to upöoad if interested. Thanks for your interest and help. Best regards Hans
