bamtools: cmake in the most recent version give errors

I am not an expert in cmake, but here is the error message:

zhouke@europa[~/src/bamtools]$ mkdir build zhouke@europa[~/src/bamtools]$ cd build zhouke@europa[~/src/bamtools/build]$ cmake … CMake Error at CMakeLists.txt:20 (message):

BamTools requires an out of source build.
$ mkdir build 
$ cd build
$ cmake ..
$ make 

(or the Windows equivalent)

Call Stack (most recent call first): CMakeLists.txt:24 (ensure_out_of_source_build)

– Configuring incomplete, errors occurred!