Are the commands "cmake -build . --target package" and "cpack ." equivalent?

Are the commands “cmake -build . --target package” and “cpack .” fully equivalent?

If yes, why would one ever use the former?

(One possible reason I know: Under Windows, cpack is ambiguous, as Chocolatey has an obsolete cpack.exe.)

They are more or less equivalent, yes. The package target exists so you can run make package or ninja package. Running cmake --build . --target package does seem a little silly to me… if you’re using the CMake command line tools anyway, you might as well use cpack at that point.

The cmake --build . --target package command is logically equivalent to running cpack, but there are important differences:

  • I think cmake --build . --target package will also build the all target first, whereas running cpack directly won’t. Perhaps @kyle.edwards can confirm this?
  • Running cpack directly supports many options that allow you to control the behavior (e.g. specifying which package generators to use), whereas cmake --build . --target package can only support the defaults set by the project.
  • If you want to create a multi-config package, you can do that by invoking cpack -C .... There is no equivalent for cmake --build . --target package, which can only build/package a single configuration.

Yes, package is a build-in target in CMake with dependeny to ALL.

I mentioned that here yesterday:

cpack . will also run the install target on your project, so it also basically has a dependency on ALL as well.

Turns out that’s not accurate. cpack will run the cmake_install.cmake script, it won’t build the install target. I did some local testing to confirm that my original comment was correct: cmake --build . --target package will also build the all target first, whereas running cpack directly won’t.


Hmm, guess I was mistaken then. There was definitely some reason I had split the packaging steps out from the main build in our superbuilds, but maybe that was due to looking to support different packaging layouts with a single build tree (where install dirs depend on the packaging format).