Airship\Hangar\Commands\Assemble::getGitCommitHash PHP Method

    public function getGitCommitHash() : string
    {
        $projectRoot = $this->session['dir'];
        if (!\is_dir($projectRoot . '/.git')) {
            throw new \Exception(".git directory not found!");
        }
        $command = "/usr/bin/env bash -c 'echo OK'";
        if (\rtrim(\shell_exec($command)) !== 'OK') {
            throw new \Exception("Can't invoke bash");
        }
        $dir = \getcwd();
        \chdir($projectRoot);
        $hash = \rtrim(\shell_exec("git rev-parse HEAD"));
        \chdir($dir);
        return $hash;
    }