This inserts low-level hooks for interactive step-by-step debugging.
Hooks are triggered by setting the *TEST* environment variable.
This is particularly useful for tracking down file descriptor leaks,
double-closing, or other issues which are difficult to debug with
the usual toolbox.
Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Upstream-commit: 1737063904dbcc311bee64b4c48548549006e62e
Component: engine
865e951d26