CMakeDeps issue

This repo shows the issue I am currently having with CMakeDeps and transitive tool_requires/requires.

The dependency chain is:

• clib has a tool_requires towards header_generator.
• header_generator has a requires towards arbitrary_dep.

To reproduce the error, run the following commands from the repo root:

conan create arbitrary_dep
conan create header_generator
mkdir -p clib/build
pushd clib/build
conan install ..
conan build ..
popd

This will generate the following error:

  Could not find a package configuration file provided by "arbitrary_dep"
  with any of the following names:

    arbitrary_depConfig.cmake
    arbitrary_dep-config.cmake

  Add the installation prefix of "arbitrary_dep" to CMAKE_PREFIX_PATH or set
  "arbitrary_dep_DIR" to a directory containing one of the above files.  If
  "arbitrary_dep" provides a separate development package or SDK, be sure it
  has been installed.

I am not sure what to do here. The CMakeDeps generated files seem to expect a reference to arbitrary_dep but is not generating these files itself. In this example, I am not interested in a CMake reference to arbitrary_dep, only to header_generator.

I found this issue on Github: conan-io/conan#9951, where this is supposedly solved by adding force_host_context=True to the tool_requires call. I am not sure if that is what we are after, however, since header_generator is used to actually build the clib package, not test it (hence I am hesitant to use test_requires which I guess tool_requires(..., force_host_context=True) will turn into in conan 2.0?).