>> libsrtp2-dev needs pkg-config only when I compile it myself. > The libsrtp2-dev package surely both depends and build-depends on > pkg-config.
Yes, the package description (debian/control) does. The created files do not. I can compile, link, and run with libsrtp2.so without pkg-config. Actually for this package, the result of pkg-config is wrong (--cflags is empty, --libs lists -lpcap unnecessarily). However, that is another issue (although it might be the cause why it was declared as Depends). > [For libgtk-3-dev y]ou cannot really expect anyone to get this right > without pkg-config, and so libgtk-3-dev depends on pkg-config. Yes, my assumption might not be right for every package in that list. Therefore, I would love to see someone more experienced taking over this issue. Your argument is a strong argument for at least Suggests. However, even in this example, pkg-config is not required. In such a case, one can argue for Recommends instead of Suggests. Nevertheless, I would not go for Depends. That is what I am about. Perhaps someone sees a pattern and comes up with a general rule. For example: "Every package with a pkgconfig/*.pc file has to Suggest pkg-config†. If the shared library does not declare its dependencies itself, and additional libraries are required to run the shared library, pkg-config has to be Recommends. pkg-config should never be Depends because the developer might have other means to build." Again, the last sentence could be wrong if there is a dedicated config tool in the package itself, which actually relies on pkg-config. Another example: libxml2-dev » libicu-dev » libicu-le-hb-dev » libharfbuzz-dev » libglib2.0-dev » pkg-config Only because of the dependency graph, pkg-config must be installed. Again, pkg-config is not required to compile/link against libxml2. Actually, the package itself declares pkg-config just as Suggests. Perhaps this is a bad example as well, because there is a bug in the dependency graph. Anyway from that 250 packages, I have just looked in-depth into libxml2 and libsrtp2, yet. † That part of "my" rule would affect another several hundred packages.
