CMake/CPack: Preferred package generators for different platforms

Question

I want to distribute executables and libraries of a C/C++ project on Linux, OSX and Windows. What are the preferred CPack generators, i.e. which are likely to be available for most users? On Windows there only seems to be NSIS, but on Linux and OSX there are several alternatives. By the way, a source distribution is generated as well, so in theory, users of all platforms should be able to compile the code themselves, but we want to provide precompiled binaries for convenience.

Answer 1

There are multiple common practices on each of the different platforms. Which one is best for you will depend on a variety of factors, but the following should at least help choose among the more popular formats that CMake/CPack has direct support for. I'm assuming you are using CPack via CMake (i.e. via the CPack module, possibly with package components using the CPackComponent module as well).

Windows:

• The NSIS package generator produces executable installers which average users are well accustomed to using. These support component-based installs, so you could provide the source as an optional component. CMake's support for this package generator is fairly mature, but it is perhaps becoming a less preferred method in recent times.
• The WIX package generator produces MSI installers. Support for this is newer and seems to be more active in terms of feature development, etc. It also supports component-based installs and seems to be becoming the preferred format over NSIS.

Mac

There are a number of options to choose from for Mac, but which one is most appropriate depends on what you want to package up. If you just want to provide a single app bundle, the DMG package generator (also sometimes referred to as the DragNDrop generator) is probably what you want. Users are well acquainted with these and they are easy to use. Avoid the Bundle generator, it is older and more limited in what it supports, the DMG generator should be preferred instead.

For packages containing more than a single bundle, the DMG generator is still potentially suitable, but a proper installer may be more appropriate. Until recent years, the PackageMaker generator was the go-to generator for that, but it has been superseded by the ProductBuild generator (supported by CMake since version 3.7).

Linux

On RedHat-based systems, RPM is usually the package format of choice (use the RPM generator), whereas for Debian-based systems the DEB format is preferred (use the DEB generator). Debian-based systems can support RPM using tools like alien, but users almost always prefer a native DEB format. If you're happy to provide both, you can keep both camps happy, but note that you will have to pay careful attention to binary compatibility. Simple packages used to be able to build against the LSB (Linux Standards Base) to produce a single RPM that would work on all major Linux distributions (even Debian-based ones), but the LSB hasn't really kept up with recent developments and it never really supported the full set of functionality most complex apps needed (or the versions of packages they provided were too old). The LSB does, however, provide very useful tools like the app checker for assessing whether packages you've built (by any means) will be missing symbols, etc. across various Linux distributions.

Note that for Linux, you should distinguish between whether you are targeting packaging for inclusion in Linux distributions themselves or whether you expect users to download and install the packages outside of the distribution's packaging system. Larger independent commercial software products will tend to be distributed as standalone packages, including the relevant libraries, etc. and installing under /opt by default (if they follow guidelines like those advocated by the LSB and Filesystem Hierarchy Standard - FHS (PDF)). Ideally, you would make your packages relocatable so that distribution maintainers have an easier time adapting your packaging method to their distribution's requirements.

RPM and DEB both support source packages to some degree.

Cross-platform

• The IFW package generator is favoured by some as a way to produce installers which have a similar look and feel across all platforms. It is also quite progressive in offering support for features like downloadable components. If having an easy-to-use graphical installer across all platforms is of interest, then this one is probably what you're looking for.
• The Archive package generator provides support for archives like ZIP, tarballs, 7z and more. These are very basic formats that simply lump your files together into a single archive. These don't have the useful features like desktop integration, pre-/post-install and uninstall, but they are handy as a second alternative package format to one of the above. In particular, they can be useful for users who don't have admin access on their systems and want to simply unpack to a convenient location.