If you are building a program, install the -dev package. Numbered -dev packages are usually not relevant; there should be an unnumbered one that forwards if nee

If you are building a program, install the -dev package. Numbered -dev packages are usually not relevant; there should be an unnumbered one that forwards if needed. During the build of a program, you record which numbered suffix (= ABI version, should be the same as the .so.N suffix but that's not how you look it up; this allows you to install multiple incompatible copies of the library and they will be used by the appropriate, though distros usually prune these after each major release) is used. This should be automatic. (if there's more than one number, all but the last are part of the library name itself. There might be exceptions for BSD-style libraries?) When installing, you should be automatically using the dependency you recorded during the build.