Steps to reproduce

There needs to be a way to add extra cmake prefixes to certain proprietary packages where the odds of getting it fixed upstream is unlikely.

Create a package (foo) with the following

    def setup_dependent_build_environment(self, env, dependent_spec):
        if self.spec.satisfies("target=x86_64:"):
            env.append_path("CMAKE_PREFIX_PATH", self.prefix.targets + "x86_64-linux/lib/cmake")

Then create a package (bar) that depends on that package (foo), and attempt to install that package (bar).

bar will not have the prefix path $foo_prefix/targets/x86_64-linux/lib/cmake provided which causes it to fail. Providing this as an environment variable doesn't work because spack passes this flag as a command line flag which has higher precedence.

I think the fix is to check this environmental variable in get_cmake_prefix_path(pkg) in build_environment.py or in build_systems/cmake.py, but I wasn't sure how to do that.

Error message

Example for a modified cuda package and a package that depends on CUB (a part of CUDA) cusz

Information on your system

• Spack: 0.18.0.dev0 (a9a08cb)
• Python: 3.10.5
• Platform: linux-fedora36-icelake
• Concretizer: clingo

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have searched the issues of this repo and believe this is not a duplicate
• I have run the failing commands in debug mode and reported the output