gem installation fails

[usernam3]

root@94e20e2cbe12:/demo# gem install meta_commit
Fetching: meta_commit_contracts-0.1.2.gem (100%)
Successfully installed meta_commit_contracts-0.1.2
Fetching: rugged-0.26.0.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing meta_commit:
	ERROR: Failed to build gem native extension.

    current directory: /usr/local/bundle/gems/rugged-0.26.0/ext/rugged
/usr/local/bin/ruby -r ./siteconf20180304-171-sfrp06.rb extconf.rb
checking for gmake... no
checking for make... yes
checking for cmake... no
ERROR: CMake is required to build Rugged.
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/usr/local/bin/$(RUBY_BASE_NAME)
	--with-sha1dc
	--without-sha1dc
	--use-system-libraries

To see why this extension failed to compile, please check the mkmf.log which can be found here:

  /usr/local/bundle/extensions/x86_64-linux/2.3.0/rugged-0.26.0/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /usr/local/bundle/gems/rugged-0.26.0 for inspection.
Results logged to /usr/local/bundle/extensions/x86_64-linux/2.3.0/rugged-0.26.0/gem_make.out

Got this error while running gem install meta_commit

[usernam3]

meta_commit uses rugged gem to access commit diffs and traverse git repository.
It is the known behavior that rugged requires cmake to be installed, so before you run gem install meta_commit you need to have cmake installed.
To fix this problem you need to run :

Mac OS

    $ brew install cmake

Linux

    $ apt-get -y install cmake