You can clone with
HTTPS or Subversion.
On composer install and also on update i get a Fatal error on Mercurial repos:
PHP Fatal error: Class 'Composer\Repository\Vcs\Filesystem' not found in phar:///usr/local/bin/composer.phar/src/Composer/Repository/Vcs/HgDriver.php on line 47
Is this a bug or a misconfiguration on my side?
Add missing `use` in HgDriver
D'oh, bug. I merged @stloyd's fix. Run self-update in a few minutes and it should work again.