Re: variables defined in the makefile are ...

[Paul Smith]

On Mon, 2016-01-04 at 08:07 +0800, 積丹尼 Dan Jacobson wrote:
> PATH=$$PATH:../v4
> PATH=$(PATH):../v4
> PATH=/home/jidanni/bin:/usr/bin:/bin:../v4
> PATH+=:../v4
> 
> Is to use the third version,
> as the first will cause "ATH",
> the second a recursive error,
> and the fourth a blank in PATH that will cause any pipes commands to
> burst...

The right way to do this, as with any other variable you want to assign
to itself (PATH is not special), is to use simply-expanded variables
(:=)

  PATH := $(PATH):../v4