Disable testing when using BUILD_TESTING

[pfultz2]

CMake uses this variable to enable/disable tests in their CTest module(which is why the variable name is highlighted by github as a special value).

More importantly, it allows pybind to be installed directly with cget with cget install pybind11/pybind since cget also sets BUILD_TESTING to Off when not testing a package.

It will still default to On when pybind is not a master project, and Off when it is not.

[wjakob]

Seems reasonable, but can't you do this without introducing a redundant option (which already exists internally in CMake). This will probably not work, but something like:

option(PYBIND11_TEST    "Build pybind11 test suite?"     ${BUILD_TESTING} AND ${PYBIND11_MASTER_PROJECT})

[wjakob]

ping?

[pfultz2]

Seems reasonable, but can't you do this without introducing a redundant option

That option only exists if you include CTest, and it will default to On always. This will set the default based on whether its a subproject.

This is also similar to the BUILD_SHARED_LIBS variable. It is recommended to set it by default to On in the project when you want the library to be built as a shared library(but the user can override the variable to get a static library), from BUILD_SHARED_LIBS:

This variable is often added to projects as an OPTION so that each user of a project can decide if they want to build the project using shared or static libraries.

[henryiii]

I thought I'd fixed issues like this, but my logic for BUILD_TESTING was not quite right.

The normal/simplest/best way to do this for a project that uses CTest (which I think we should look at using later) would be:

if(PYBIND11_MASTER_PROJECT)
  include(CTest) # defines BUILD_TESTING
  if(BUILD_TESTING)
    add_subdirectory(tests)
  endif()
endif()

The downside is that you can't build the tests if this is not the master project, but in general that's not a good idea and probably not really supported anyway.