Yup! You're right as always Quinn... it's the Hardened Runtime.
Although I do seem to have HR enabled all the time in my Target. Maybe something about building for Debug or Profiling disables it...? Regardless, disabling it not only got DYLD_PRINT_LIBRARIES working, it also got the LSEnvironment flags in my Info.plist to work as well.
Thanks:)
Topic:
App & System Services
SubTopic:
Core OS
Tags: