src/Composer/Downloader/FileDownloader.php
public function download(PackageInterface $package, $path, $output = true)
    {
        if (!$package->getDistUrl()) {
            throw new \InvalidArgumentException('The given package is missing url information');
        }

        if ($output) {
            $this->io->writeError("  - Installing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>): ", false);
        }

        $urls = $package->getDistUrls();
        while ($url = array_shift($urls)) {
            try {
                $fileName = $this->doDownload($package, $path, $url);
                break;
            } catch (\Exception $e) {
                if ($this->io->isDebug()) {
                    $this->io->writeError('');
                    $this->io->writeError('Failed: ['.get_class($e).'] '.$e->getCode().': '.$e->getMessage());
                } elseif (count($urls)) {
                    $this->io->writeError('');
                    $this->io->writeError(' Failed, trying the next URL ('.$e->getCode().': '.$e->getMessage().')', false);
                }

                if (!count($urls)) {
                    throw $e;
                }
            }
        }

        if ($output) {
            $this->io->writeError('');
        }

        return $fileName;
    }
public function download(PackageInterface $package, $path, $output = true)
    {
        if (!$package->getDistUrl()) {
            throw new \InvalidArgumentException('The given package is missing url information');
        }

        if ($output) {
            $this->io->writeError("  - Installing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>): ", false);
        }

        $urls = $package->getDistUrls();
        while ($url = array_shift($urls)) {
            try {
                $fileName = $this->doDownload($package, $path, $url);
                break;
            } catch (\Exception $e) {
                if ($this->io->isDebug()) {
                    $this->io->writeError('');
                    $this->io->writeError('Failed: ['.get_class($e).'] '.$e->getCode().': '.$e->getMessage());
                } elseif (count($urls)) {
                    $this->io->writeError('');
                    $this->io->writeError(' Failed, trying the next URL ('.$e->getCode().': '.$e->getMessage().')', false);
                }

                if (!count($urls)) {
                    throw $e;
                }
            }
        }

        if ($output) {
            $this->io->writeError('');
        }

        return $fileName;
    }
{@inheritDoc}