If dependencies are a problem, you could always use the pre-compiled version from cmake.org. It uses the bundled 3rd party libs.
I prefer software that uses mature 3rd party libs over NIH driven rewrites. Please also keep in mind that CMake is available for many platforms sone with fading user base like AIX, HPUX, or Solaris. Using a well tested event library like libuv helps to keep those supported.
What does it require over and above what you'd need for development anyway? The vagrant provision script for my Ubuntu VM installs this lot before grabbing the CMake source and building it:
apt-get -y install subversion git make gcc g++ subversion emacs git-gui zip gksu synaptic gdb valgrind
I'm pretty sure that not all of these are actually required. You do need gcc and g++, I'm sure, but I expect Valgrind and GDB are strictly optional...
The emacs dependency is odd to say the least, but I'm pretty sure CMake doesn't actually depend on it. I don't know much about Gentoo but perhaps the question mark after it means it's just a suggested dependency.
Perhaps they configured it that way? Maybe these are optional dependencies that provide additional functionality.
I was able to build it on a Ubuntu VM after installing no more than gcc, g++ and make.
apt list --installed suggests this VM does have a surprising amount of stuff installed (more than I'd expected at any rate), but of the dependencies you list it appears to have zlib, curl, and nothing else.
I also build CMake from source on Ubuntu (because they used to ship ridicously ancient versions and I have keep doing it since) and there is the possibility to use bundled versions of those dependencies.
Also, for a development tool I see nothing wrong with those dependencies, I do not have to redistribute all of this.
And for those compiling everything from source like Gentoo or FreeBSD ports users, I do not understand it because most of the time is spent on building gcc or clang anyway which is absolutely not optional.
Every dependency increases the fragility of your program. What if you update the dependency and it breaks your program? What if you have two programs dependent on the same library -- but different versions? This just scratches at the surface of the problem.
Sometimes the risk is worth it: you need some complex functionality not worth writing yourself. In that case it's a good thing. But understand that it's a tradeoff.
This is a very dangerous argument for anything but the most domain specific or simple logic. Every time I roll something non trivial rather than using the widely testing and "battle hardened" alternative that increases the fragility of my program.
There are times when it makes sense, but those are the special cases, and carry a cost which should be considered.
> you need some complex functionality not worth writing yourself.
well, CMake supports downloading stuff from the internet - git repositories, etc. If you want to be able to download from https:// addresses I sure hope that you won't reimplement it yourself.
Some CMakefiles have many and gratuitous dependencies but that's the fault of those authors.