The CMakeLists.txt contains code that seems to assume that you will build with 
make when using a gcc-compitable compiler, this results in invalid build files 
for atleast the Ninja build system.

What steps will reproduce the problem?
1.  Go into the yaml-cpp source root directory: 
2.  Run mkdir ninjabuild
3.  cd ninjabuild
4.  cmake .. -G "Ninja"
5.  ninja

What is the expected output? What do you see instead?

Expected build to be successful, instead it results in the following error:
ninja: error: build.ninja:225: bad $-escape (literal $ must be written as $$)


What version of the product are you using? On what operating system?
yaml-cpp 0.5.1, building on Ubuntu

Please provide any additional information below.

As far as I can discern the line 145 to 152 in the root CMakeLists.txt seems to 
be the problem. Specifically the use of $(MAKE) in both add_custom_target 
calls, as the build works with make I would assume that this results in valid 
makefiles. If so it might be a good idea to check that you are generating for 
makefiles and skip this part if it is generated for another build system 
instead.