[CMake] Re: Re: Re: FindQt4 in 2.4.8 bug

[Fernando Cacciola]

Hi Bill,

> OK, I get it now...   So, the FIND_* stuff will set a value if it is 
> NOTFOUND.
Yes.

> However, the set command will not.

Right, and as yoy said down thread, it won't only if using  CACHE as only 
then it gives prior values precedence.

>  I am thinking it should.

At the very least it should have had.

>     I am not sure what that will break, but it would be consistent with 
> FIND_*.
>
> This should not be a problem if you start from a clean build tree for 
> FindQt4.cmake, as QT_INCLUDE_DIR will never get put in the cache as 
> NOTFOUND by the current FindQt4.cmake.
>
Right.
As I am now aware of the problem I can at least tell me users to clean the 
cache and try again if anything doesn't work.
(Along with another rule of thumb I've learned so far which is to run cmake 
twice, also related to the cache behaviour)

Best

Fernando