difficulty installing root

I'm trying to install root but am having the following issues. Please help me

CMake Error at /home/joydev/Apps/root/root_build/AFTERIMAGE-prefix/src/AFTERIMAGE-stamp/AFTERIMAGE-build-Release.cmake:49 (message):

Command failed: 2

'/usr/bin/gmake'

See also

/home/joydev/Apps/root/root_build/AFTERIMAGE-prefix/src/AFTERIMAGE-stamp/AFTERIMAGE-build-*.log

gmake[2]: *** [CMakeFiles/AFTERIMAGE.dir/build.make:86: AFTERIMAGE-prefix/src/AFTERIMAGE-stamp/AFTERIMAGE-build] Error 1

gmake[1]: *** [CMakeFiles/Makefile2:5621: CMakeFiles/AFTERIMAGE.dir/all] Error 2

gmake: *** [Makefile:156: all] Error 2

joydev@joydev-VirtualBox:~/Apps/root/root_build$

Please, someone, help me.

I am following this \

$ cd $HOME

$ # creat the Apps directory if not already present

$ mkdir Apps

$ cd Apps

$ git clone http://github.com/root-project/root.git

$ cd root

$ git tag -l

$ # git tag -l will list all available tags. In the next command choose the tag v6-22-06

$ # or the latest official release number

$ git checkout -b v6-22-06 v6-22-06

$ # now ROOT is ready to be configured. Below you will find the minimal ROOT configuration needed. $ # since we are using cmake build now, first we will need to create the build directory.

$ mkdir root_build

$ cd root_build

$ cmake ../ -Dgminimal=ON -Dasimage=ON -Dmathmore=On -Dminuit2=ON -Dxml=ON -DCMAKE_INSTALL_PREFIX=../root_exec

$ # next will be the make called via cmake. If running on a multicore CPU you can speed up tremendously by $ # calling it with the option -j , where is the number of threads which you want to give, $ # e.g. cmake --build ./ --clean-first -- -j8

$ cmake --build ./ --clean-first

$ # as a last step of the ROOT build process we need to install it

$ make install