So, this feature is now supported in superdirt from v1.7.3 (ie you don't have to muck about in a dev branch of git)
[edit] first up, can you post the file where you call doNotReadYet? It looks like there might be a spurious underscore...
Failing that, continue here:
I don't know, but it looks like your quark update request didn't go anywhere and may be because you didn't specify a tag (and I just saw that command recommended in the docs, so it may need review).
Try this:
Quarks.checkForUpdates({Quarks.install("SuperDirt", "v1.7.3"); thisProcess.recompile()})