The solution (as I noted here) is pretty simple:
- Reboot into Recovery Mode (hold down ⌘R during boot)
- Launch a shell and run
csrutil enable --without dtrace
- Reboot and allow machine to boot normally
Embarrassing story time:
This is neatly documented by Brian Bennett in a StackExchange post (from 2015!). Not only that, but I even left myself a breadcrumb linking to that StackExchange post in May of 2016. But sadly none of that stopped me from taking to Twitter to ask how to solve this problem.
Oh well. At least now I can successfully run the test suites for libusdt and my Python wrappers for it locally on my laptop.