This directory contains make rules for helping debug the make environment and project rules (e.g., printing the values of environment variables, etc.).

Usage: make <command> [<ENV_VAR>=<value> <ENV_VAR>=<value> ...]

Prints the runtime value of a Makefile variable.

$ make inspect.CC

$ make inspect.ROOT_DIR

Asserts that a Makefile variable is set.

$ make assert.CXX

If a variable is not set, the command exits with a non-zero exit code.

Prints a sorted list of Makefile variable names.

$ make list-variables

To remove duplicates, pipe to uniq. Note that the list of variables is not exhaustive, as the list does not include built-in variables.