I am not planning to build or download or whatever one needs to do to work with flatpak. I’m sure it’s the greatest thing since hotcakes were invented. But I don’t want to learn how to use flatpak.
OK, starting over this time on my Gentoo computer (so I don’t have to keep running upstairs to the other computer) 
:
-
I already have dev-util/meson-0.46.1 installed from portage.
-
At the command line I established my prefix for building GIMP from git.
-
I cloned json-glib.
-
I cd’ed to the just-cloned json-glib source code folder.
Now what do I type next? Do I make a build folder inside the json-glib folder? If so, what do I call it?