error: unsupported operation: can't call foreign function `not_exported` on $OS
  --> tests/native-lib/fail/private_function.rs:LL:CC
   |
LL |         not_exported();
   |         ^^^^^^^^^^^^^^ can't call foreign function `not_exported` on $OS
   |
   = help: if this is a basic API commonly used on this target, please report an issue with Miri
   = help: however, note that Miri does not aim to support every FFI function out there; for instance, we will not support APIs for things such as GUIs, scripting languages, or databases
   = note: BACKTRACE:
   = note: inside `main` at tests/native-lib/fail/private_function.rs:LL:CC

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to 1 previous error