My toy project that I ported from a Gtkmm article done in the days of "The C/C++ Users Journal" takes around 25 minutes to build from scratch on a Asus 1215B netbook (dual core, 8GB, HDD).

The original code, after being migrated to an up to date version of Gtkmm, takes a couple of seconds with GCC 7, not more than one minute if at all.

The big difference? I don't need to compile from scratch all the 3rd party dependencies.

With every release from Rust I do a clean build to assert how much it has improved.

It was much worse, so congrats on the work achieved thus far, but it is still a pain to set up a project from scratch.