build cmake against system libs

[William A. Hoffman]

At 07:20 PM 9/9/2006, Matt Rogers wrote:
>On Saturday 09 September 2006 17:26, Alexander Neundorf wrote:
>> On Sunday 10 September 2006 00:13, Dirk Mueller wrote:
>> > Hi,
>> >
>> > I've noticed that cmake contains deep copies of various 3rd party
>> > libraries, including really old versions of libcurl and zlib. I created a
>> > hackish patch to make it build against the system version of those
>> > libraries.
>>
>> I think Matt Rogers already sent a similar patch to the cmake mailing list
>> some weeks ago. The CMake devs *want* to ship and link to their included
>> versions, so that the cmake binary has as few dependencies as possible (I
>> think this was the reasoning).
>>
>> Bye
>> Alex
>
>I at least proposed it, but it was almost immediately shot down for some 
>pretty lame reasons, IMHO.

I suppose I should defend the position.   There are several reasons:

1. The nightly regression tests with cmake are done with the same code base.
Any upgrades of libraries used, may or may not be compatible.   So, bugs
maybe introduced, and fielding the bug reports will be more difficult.

2. It will make the cmake files for cmake more complicated.  

3. We want the build to be as simple as possible.  You download one set
of sources and you are done.   No Easter egg hunt for packages.  This is
very important for windows, and UNIX.   One of the big complaints about
CMake is that you have to build/install it before you can use it.  If someone
is using CMake, the requirement should be a C++ and C compiler, and that is
all. 

However, there seems to be enough of an outcry here, that I suppose we
should reconsider.   Having an option that defaults to off could be done.
BTW, the zlib is very recent.  Curl is not, mostly because
the upstream Curl does not have CMakeLists.txt files in it.   We are going
to work on that.

-Bill

-Bill