CMake on Linux CentOS 7, how to force the system to use cmake3?
I tried to install PyTorch on my Linux CentOS 7.3. I downloaded its package, ran this command and got this error:

sudo python setup.py install

running install
running build_deps
CMake Error at CMakeLists.txt:1 (cmake_minimum_required):
  CMake 3.0 or higher is required.  You are running version 2.8.12.2


-- Configuring incomplete, errors occurred!


So I tried to install CMake 3 by using the command 

sudo yum -y install cmake3


The installation went alright, but the system still uses cmake2.8 as default.
If I type the yum info comnmand, I get this:

sudo yum info cmake

Installed Packages
Name        : cmake
Arch        : x86_64
Version     : 2.8.12.2
Release     : 2.el7
Size        : 27 M
Repo        : installed
From repo   : base
Summary     : Cross-platform make system
URL         : http://www.cmake.org
License     : BSD and MIT and zlib
Description : CMake is used to control the software compilation process using simple
            : platform and compiler independent configuration files. CMake generates
            : native makefiles and workspaces that can be used in the compiler
            : environment of your choice. CMake is quite sophisticated: it is possible
            : to support complex environments requiring system configuration, preprocessor
            : generation, code generation, and template instantiation.


So, the problem is clear: the system still sees cmake2.8 as default, and therefore Python does not use cmake3 for its PyTorch installation.
How can I solve this problem?

Thanks

Once you have both the cmake and the cmake3 package installed on your machine, you can use update-alternatives to switch between both packages.
Use the alternatives command to register both installations:
$ sudo alternatives --install /usr/local/bin/cmake cmake /usr/bin/cmake 10 \
--slave /usr/local/bin/ctest ctest /usr/bin/ctest \
--slave /usr/local/bin/cpack cpack /usr/bin/cpack \
--slave /usr/local/bin/ccmake ccmake /usr/bin/ccmake \
--family cmake

$ sudo alternatives --install /usr/local/bin/cmake cmake /usr/bin/cmake3 20 \
--slave /usr/local/bin/ctest ctest /usr/bin/ctest3 \
--slave /usr/local/bin/cpack cpack /usr/bin/cpack3 \
--slave /usr/local/bin/ccmake ccmake /usr/bin/ccmake3 \
--family cmake

After these two commands, cmake3 will be invoked by default, when you enter cmake from a bash prompt or start a bash script. The commands also take care of registering a few secondary commands like ctest which need to be switched along with cmake.
If you need to switch back to cmake 2.8 as the default, run the following command:
$ sudo alternatives --config cmake

There are 2 programs which provide 'cmake'.

  Selection    Command
-----------------------------------------------
   1           cmake (/usr/bin/cmake)
*+ 2           cmake (/usr/bin/cmake3)

Enter to keep the current selection[+], or type selection number: 1

