Chris Marsh

@stalexja that link results in a 403 so noone can view it

I rebased this PR on develop and I'm seeing the following build error ``` ==> Installing cmake-3.30.2-ylbdewin44le3plnp77jd2paeodaacpk [73/209] ==> No binary for cmake-3.30.2-ylbdewin44le3plnp77jd2paeodaacpk found: installing from source ==> Fetching https://github.com/Kitware/CMake/releases/download/v3.30.2/cmake-3.30.2.tar.gz...

So far this PR seems to be working well for me on gentoo. This change https://github.com/spack/spack/commit/c4dd67b7a54eb5f6e80c199c75e5407438c6200d got me back up and running after I rebased this on a more recent...

Unhelpfully, this looks similar to https://github.com/shenxn/protonmail-bridge-docker/issues/32

The way the non-gmp backend works is a bit unclear for autotools consumers. I do wonder if this would be handled via a[setup_dependent_build_environment](https://spack.readthedocs.io/en/latest/spack.html#spack.builder.Builder.setup_dependent_build_environment) but it then has to conflict against...

Upon further reading it is not at all clear to me how the non-gmp variant should work. The variable doesn't seem to be cached (although it seems like it should...

Apologizes-- I thought I had converted it to a draft. I was waiting on the reply to https://github.com/CGAL/cgal/issues/8606 to decide how to go forward with the `+gmp` variant. I cannot...

I have removed this from the package.py but pasting it here for completness incase we need to revist this in the future. This is what I was trying, based off...

@psakievich Ok, this should be ready for review. I decided to keep the `+gmp` variant as it does impact the `depends_on` on `gmp` and `mpfr`. There are some stale `depends_on`,...