> > > > > Patch below adds support of a BUILD_BROKES_WHEN_INSTALLED > > > > > variable. If this variable is set, port's building process will > > > > > be prohibited if some version of port is already installed. > > > > > Glib2 is a good example of a port needs such prohibition. > > > > > > > > > > No manpage changes yet, I want to get response for the idea > > > > > first. > > > > > > > > The build is not *always* broken when the libs are installed > > > > beforehand. Your change would make it a lot slower to get some > > > > things (e.g. small security fixes that don't change the library > > > > functions) tested. > > > > > > Well, make BUILD_BROKES_WHEN_INSTALLED=No will help in that case... > > > But, of course, this is ugly. > > > > But it changes from version to version. An update that doesn't > > change library functions is no problem... > > Mmmmaybe slightly modified version at the end of letter, which ignores > same version with actual one will be good enough?
No, this doesn't make much sense. Like Stuart said, it depends. Most of the time, ports can be built if another version is installed. Problems usually occur if a port wants to link newer code to incompatible older libraries. The software's build system should just look in the right place to link it to the newer library - many ports use GNU libtool, which looks in the wrong place first.
