[CMake] [PATCH] slightly modify cache variable behaviour, Was: Re: option() behavior

[Alexander Neundorf]

On Monday 11 May 2009, Bill Hoffman wrote:
> So, CMake has done what it does now from the start.   There was a short
> period of time when it did not, and that was when a re-write was done,
> and it quickly broke some existing projects.  Here is the thread:

Yes, I can imagine that.
Still the current behaviour is not very intuitive, especially that set(CACHE) 
in the first cmake run overrides the "visible" variable, while the set(CACHE) 
in the second run basically does nothing, and so the value of the "visible" 
variable is different.
I think for CMake 2.8 or 3.0 it would be a good idea to make this more 
consistent and easier to understand (especially since now more and more 
people are using cmake).

> http://www.cmake.org/pipermail/cmake/2007-March/013204.html
>
> I think the rule should be if you want to change a variable you have to
> have the set AFTER the variable, or use CACHE INTERNAL.

What do you mean exactly with "have the set after the variable" ?
Have the set(FOO <value>) after the set(FOO <value> CACHE), or something 
else ?

Alex