## With Gentoo repos.conf:
sudo /bin/bash -c 'echo "[ace-overlay]  
location = /usr/local/portage/ace-overlay  
sync-type = git  
sync-uri = http://git.lan/ace/ace-overlay.git  
auto-sync = yes  
clone-depth = 0" > /etc/portage/repos.conf/ace-overlay.conf'

## With Layman:
curl -k --request GET "http://git.lan/ace/ace-overlay/src/master/ace-overlay.xml" 2>/dev/null | python2.7 -c 'import sys, json, base64; print base64.standard_b64decode(json.load(sys.stdin)["content"])' > /tmp/ace-overlay.xml

sudo layman -o file:///tmp/ace-overlay.xml -f -a ace-overlay