[Too]

Invoking the command twice can also screw up things if you run parallel build, which you should always do! Not only to speed things up it's also a good way to verify that your make file actually is correct. If your make file doesn't work in parallel build it is broken, in the same way as C code that breaks at -O2 and above due to reliance on undefined behavior.

The solution to the multiple target problem is using the built in magic .INTERMEDIATE rule which isn't entirely obvious how it works.