RFC: PKG_CHECK_MODULES() should honor ${libdir} and ${datadir}

[Peter Johansson]

Hi Tollef.

On 3/26/10 5:13 PM, Tollef Fog Heen wrote:
> Are you worried about people being confused why configure with
> --prefix=$HOME works, but not without or something else?  My first worry
> was «what happens when you have multiple .pc files with the same name»,
> since that's a situation which we don't deal with too well today and
> starting to mangle the search path would make this into a more common
> situation causing confusion.
>
>    
Yes, one case I was thinking of was when you have different .pc files 
under $HOME and /usr/local. A similar case is that you have foo.pc 
installed in $HOME but not in /usr/local. That would typically mean that 
configure works if I set prefix=$HOME but not if I use default 
prefix=/usr/local. Another case in which we often set prefix is in 
autoamke's 'make distcheck'. Just to be clear: say that you have foo.pc 
installed in /usr/local. So with the suggested change pkg-config will 
find the foo.pc during the normal `./configure' because default is 
--prefix=/usr/local. Then during 'make distcheck' the rule runs 
`./configure --prefix=$$dc_install_base', which means pkg-config will no 
longer look in `/usr/local' and the configure call will fail. And in 
many cases it would be confusing and very difficult to understand why 
'make distcheck' fails.

Thanks,
Peter