Re: Override directive usage

[Paul Smith]

Quoting Steve Deiters <address@hidden>:

> Using make 3.81, any subsequent regular variable assignments to a
> variable previously assigned using an override directive are ignored.
> For example, in the following:
>
> ---     1969-12-31 18:00:00.000000000 -0600
> +++ Makefile    2009-08-20 16:55:07.000000000 -0500
> @@ -0,0 +1,6 @@
> +FOO:=foo
> +override FOO+=bar
> +FOO+=baz
> +
> +all:
> +       @echo $(FOO)
>
> The output is "foo bar" instead of the expected "foo bar baz".  Is this
> the expected behavior?  I would expect all regular assignments would be
> valid unless overridden by values on the command line.

This behavior is expected.  Make tracks variables internally with a certain
level of "importance".  Once a variable is set to a certain level, then
no assignment of that variable via a method of lesser "importance" takes
effect.  The highest level is "override", so once a variable is marked
"override" no other assignment, except another override, can change it.