[nwmcsween]

Gentoo lists:

    app-crypt/rhash
    >=app-arch/libarchive-3.0.0:=
    >=dev-libs/expat-2.0.1
    >=dev-libs/libuv-1.10.0:=
    >=net-misc/curl-7.21.5[ssl]
    sys-libs/zlib
    virtual/pkgconfig
    emacs? ( virtual/emacs )
    system-jsoncpp? ( >=dev-libs/jsoncpp-0.6.0_rc2:0= )

of which most have dependencies as well which is honestly ridiculous for a build system.

[pedrocr]

Those look like exactly the kinds of dependencies I'd go for if I needed to write a new C build system. Nothing ridiculous about them.

[quietbritishjim]

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.

[rleigh]

It will be the cmake-mode for editing CMakeLists.txt files.

[nwmcsween]

Anything dep a ? is optional

[tom_]

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.

[nwmcsween]

Gentoo gives 'use' flags for configurable options, I stripped those out and posted the hard dependencies.

[__flo]

FreeBSD only lists 6:

> libcurl.so : ftp/curl > libexpat.so : textproc/expat2 > libjsoncpp.so : devel/jsoncpp > libuv.so : devel/libuv > librhash.so : security/rhash > libarchive.so.13 : archivers/libarchive

https://www.freshports.org/devel/cmake/

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.