install PREFIX during packaging

[Riccardo Mottola]

Hi,

I'm facing a problem while packaging base (but i start with that, i 
suppose it will happen with many other packages)

When configuring, I specify a certain prefix /xxx/yyy
Then I build the package.

Instead of installing direclty, the package wants to install in an 
directory of its own usage, passed with PREFIX=, I was told this is a 
standard feature. Currently gnustep-base tries to install directly in 
its destination directory, which is not allowed (especially because a 
package gets built as a user and thus cannot install into a system dir)

How can I installa  gnustep package in a specific location? I suppose 
different packaging system might have face a similar scenario.

Thanks,
  Riccardo