 <p>Your problem is the space after <code>CMD=</code>. This evaluates to <code>CMD=&lt;empty string&gt; "git --version"</code>. First, the environment variable <code>CMD</code> is set to an empty string, then the command <code>git --version</code> is called. Notice that due to the <code>"..."</code> the shell really tries to execute a command <code>git --version</code> and not <code>git</code> with argument <code>--version</code>. Simple remove the space between <code>=</code> and <code>"</code> to fix this.</p>