Why declarative format? Scripting capabilities of CMake are pretty useful to solve hard problems. Without such flexibility one need to use external scripts to do things impossible in declarative form.
I solved this in a method I quite like: profiles and composition. This enables nearly the same flexibility, albeit in a different format, as CMake. We also get to avoid debugging complex CMake scripts. So you can have a debug a debug profile and asan profile and compose them into a "debug + asan" profile.
Catalyst also has hooks, to address the issue you mentioned about needing external scripts.
Why declarative format? Scripting capabilities of CMake are pretty useful to solve hard problems. Without such flexibility one need to use external scripts to do things impossible in declarative form.
I solved this in a method I quite like: profiles and composition. This enables nearly the same flexibility, albeit in a different format, as CMake. We also get to avoid debugging complex CMake scripts. So you can have a debug a debug profile and asan profile and compose them into a "debug + asan" profile.
Catalyst also has hooks, to address the issue you mentioned about needing external scripts.