directory with these commands:
cd packages
- git clone --reference .. --single-branch --branch externals/PACKAGE git://git.sv.gnu.org/srv/git/emacs/elpa PACKAGE
+ git clone --reference .. --single-branch --branch externals/PACKAGE $(git config remote.origin.url) PACKAGE
If you already have a packages/PACKAGE directory with a previous
checkout, you can update it like this: