Hello! The package Lazarus in Cauldron only works on gtk2. For working with qt is neccesary to change the line of the file spec 'export LCL_PLATFORM=gtk2' to 'export LCL_PLATFORM=qt'.
Find an example of file spec here: https://build.opensuse.org/package/view_file?file=lazarus-qt.spec&package=lazarus-qt&project=home%3Aenzokiel&srcmd5=b56e9b13184ee7e052da6b0a562a0947 Afterwards, do what it is shown on the section "Quick start guide for Linux" of the website: http://wiki.lazarus.freepascal.org/Qt_Interface Which says: - To visit: http://users.telenet.be/Jan.Van.hijfte/qtforfpc/fpcqt4.html - To download: http://users.telenet.be/Jan.Van.hijfte/qtforfpc/V2.4/bin-qt4pas-V2.4_Qt4.5.3.tar.gz - To unpack: bin-qt4pas-V2.4_Qt4.5.3.tar.gz - To copy files to /usr/lib Lazarus QT is neccessary to pack Double Commander 0.5.1. Regards, Joaquin.