instmake allows you to instrument builds with GNU Make and then analyze what happened during those builds. It saves a very detailed build log and has reports to analyze those records. The reports provide you better insight into the build, allow you to find race conditions, and to analyze the parallelism of the build.
PyAnnolib is a library that lets your Python programs read Electric Accelerator (emake) annotation files. Electric Accelerator is a build tool product from Electric Cloud. Annotation files give a very detailed description of the jobs that were run during the build, including the complete dependency graph. This library is useful for writing reports about your build, data-mining the annotation file for the complete and accurate dependency graph, etc.
For plugins too
Your idea is beneficial to other things besides GUIs that wrap CLI programs. It's also beneficial to programs that are extensible via plugins. It's probably more benenficial if these programs have a GUI, but regardless, plugins are another class of things which need to publish the options they accept, and then receive those options from an outside program.