u/Irvinin

I've just recently installed Slackware (15.0) for the first time and I have a question. What should I do if I want to rebuild some of the programs installed by system packages with different options? In case of a package from SlackBuilds this is more or less straightforward, but is there a .SlackBuild files for bult-in packages? Or should I myself figure out where is the upstream of the program and then build it from the upstream source tarball?