I exactly followed the procedure http://devdocs.magento.com/guides/v2.0/install-gde/prereq/dev_install.html#instgde-prereq-compose-cl... Hit error:
[magento_user@RHELPC /var/www/html]$ git clone -b master https://github.com/magento/magento2.git
fatal: could not create work tree dir 'magento2'.: Permission denied
Do I have to change the permission of /var/www/html/?
[magento_user@RHELPC /var/www]$ ll
drwxr-xr-x. 2 root root 4096 Dec 5 10:45 cgi-bin
drwxr-xr-x. 3 root root 4096 Dec 5 10:42 error
drwxr-xr-x. 3 root root 4096 Dec 5 10:45 html
drwxr-xr-x. 3 root root 4096 Dec 5 20:05 icons
drwxr-xr-x. 2 webalizer root 4096 Dec 5 10:45 usage
Thanks very much for help!
Check that you are logged in as the right user who has full access to the installation directory.
Post your desktop screenshot so I can check and advise you better.