dropped into existing project, where all Makefiles do the following
test to see if they're running inside docker:
ifneq ($(wildcard /.dockerenv),)
i'm pretty sure that's just asking for trouble, and i've perused a
github issue related to that:
so what is the *proper* way to detect if one is running inside a
container? the way that seems most reliable is to check /proc/1/sched.