How do I list the defined make targets from the command line?

I think you might be looking for the command make help.

When I run make help (after running cmake ..) I get the following output:

The following are some of the valid targets for this Makefile:
... all (the default if no target is provided)
... clean
... depend
etc

You could also read the Makefile that cmake auto-generates for you.

For Makefile generator build environments you could use

cmake --build . --target help

And there is the graphical output solution (example found here):

cmake --graphviz=test.graph 
dotty test.graph

See also Generating Dependency Graphs with CMake and CMake Graphviz Output Cleaner.

If you don't have dotty installed, you can still make the target dependencies visible with enabling GLOBAL_DEPENDS_DEBUG_MODE in your CMakeLists.txt:

set_property(GLOBAL PROPERTY GLOBAL_DEPENDS_DEBUG_MODE 1)

The disadavantage here is that you can't trigger it from the command line. It will always show on stderr when generating the make environment.

References

• How can I get the list of dependencies of cmake target?
• Internet Archive: "CMake: list of targets"