Makefile, ${VARIABLE}= vs. ${VARIABLE}?=

[Anonymous]

Chris Rees <utisoft at gmail.com> writes:

> On 13 February 2011 14:14, Helmut Schneider <jumper99 at gmx.de> wrote:
>> Hi,
>>
>> [helmut at BSDHelmut ~]$ grep -ir latest /usr/ports/www/apache2?
>> /usr/ports/www/apache20/Makefile:LATEST_LINK=  apache20
>> /usr/ports/www/apache22/Makefile:LATEST_LINK?= apache22
>> [helmut at BSDHelmut ~]$
>>
>> So, what's the difference between e.g. "LATEST_LINK=" and
>> "LATEST_LINK?="?

Slave ports use different LATEST_LINK, e.g. www/apache22-worker-mpm.

> ?= can be overridden in make.conf or on the command line.

`=' and `:=' can be overriden via command line, too.

> = clobbers all previous definitions.