-houtput seems to indicate that it’s optional
bturrubi at blade11 :: ./src/usnic-av-tests -j1 --debug [----] Criterion v2.3.0-rc1 [====] Running 2 tests from bind_ep: criterion: Could not spawn test instance: No such file or directory  23360 abort ./src/usnic-av-tests -j1 --debug
Oh, weird. I was going off of this paragraph:
LLDB is improving on Linux. While the debugserver has not been ported (to enable remote debugging) Linux is nearing feature completeness with Darwin to debug x86_64 programs, and is partially working with i386 programs. ARM architectures on Linux are untested. For more details, see the Features by OS section below.
Found here: http://lldb.llvm.org/status.html