build.sh require hg installed

[ephrin]

satis_1    |  >> Building Satis for the first time
satis_1    | Scanning packages
satis_1    | 
satis_1    | 
satis_1    |                                                                                                                         
satis_1    |   [RuntimeException]                                                                                                    
satis_1    |   Failed to clone http://example.com/repo, hg was not found, check that it is installed and in your PATH env.  
satis_1    |   sh: 1: hg: not found