"VAR:=<value>" is not supported on the command line

[Stefan Becker]

GNU make allows "VAR:=" on the command line. Test case:

$ cat Makefile
$(info VAR: '$(VAR)')

$ make VAR:=old -f Makefile
VAR: 'old'
make: *** No targets.  Stop.

$ ckati -c --warn VAR:=old -f Makefile
VAR: ''

[Shinichiro Hamaji]

Wow GNU make. You have a lot of unnecessary features:

> cat clvar.mk
$(info $(var))
> make -f clvar.mk 'var ?= foo' 'var += bar'
foo bar