Before you call someone "hipster", I suggest you actually learn something about the problem.

CMake is the defacto standard for building portable C/C++ software today, there is also SCons. In fact, Qt includes its own build system called qmake. All of these offer much more than the GNU Autotools ever did.

So why do these things exist when autotools are so wonderful? Well, autotools are a damn nightmare to maintain (m4 scripts anyone?) and next to impossible to use outside of the GNU ecosystem - try to use it on Windows or Android without crutches like MinGW or Cygwin.

Basically, an autotools build system is pretty much unusable except on a POSIX/Unix-like platform and even then it handles only building of the package. Not a proper installation support (e.g. support for installer building/packaging), no tests, no continuous integration/compile farm support, poorly written m4 code breaks parallel compilation, etc.

Use something like CMake which is cross-platform, works very well in most cases and a lot of cross-platform open-source C++ libs are using already.

CMake. Making easy things easy and hard things impossible. Provided most cases are easy, an acceptable solution.

Hmm, any examples for the impossible hard things? Or are you just trolling?

I think CMake is one of the best (not saying it's perfect) C/C++ build systems I've used (used jam, make, automake, qmake, scons quite comprehensively, either via choice or under duress), and there are some things that are close to impossible (or were a few years ago).

One of these was getting an executable that's built as part of a script to generate a .cpp which is then built as another lib as a further dependency within the same build - I believe that's possible now as OpenEXR does it. Similarly, I've had to run external programs that binary patch executables and had serious issues doing that.

That isn't all that hard to do, CMake routinely supports this for e.g. Swig or Qt's moc/uic/rcc tools. The code generator creates a bunch of files and those can be either built as a library or added to your normal list of sources.