public function main()
    {
        $clone = $this->getFactoryInstance('log');

        if ($this->repository === '') {
            $project = $this->getProject();
            $dir = $project->getProperty('application.startdir');
        } else {
            $dir = $this->repository;
        }
        $clone->setCwd($dir);

        if ($this->maxCount !== null) {
            $max = filter_var($this->maxCount, FILTER_VALIDATE_INT);
            if ($max) {
                $max = (int) $this->maxCount;
            }
            if (!$max || (int) $this->maxCount <= 0) {
                throw new BuildException("maxcount should be a positive integer.");
            }
            $clone->setLimit('' . $this->maxCount);
        }

        if ($this->format !== null) {
            $clone->setTemplate($this->format);
        }

        if ($this->revision !== '') {
            $clone->setRev($this->revision);
        }

        try {
            $this->log("Executing: " . $clone->asString(), Project::MSG_INFO);
            $output = $clone->execute();
            if ($this->outputProperty !== null) {
                $this->project->setProperty($this->outputProperty, $output);
            } else {
                if ($output !== '') {
                    $this->log(PHP_EOL . $output);
                }
            }
        } catch (Exception $ex) {
            $msg = $ex->getMessage();
            $p = strpos($msg, 'hg returned:');
            if ($p !== false) {
                $msg = substr($msg, $p + 13);
            }
            throw new BuildException($msg);
        }
    }