Once I installed Phabricator, and when running git clone I noticed an error:
git clone https://admin@hg.ixnfo.com:443/diffusion/5/git/
Cloning into ‘git’…
fatal: unable to access ‘https://hg.ixnfo.com:443/diffusion/5/git/’: The requested URL returned error: 500
As it turned out, Phabricator could not find git-http-backend, it was also written about this in the repository settings in the Phabricator panel, for this I made a link:
sudo ln -s /usr/lib/git-core/git-http-backend /usr/bin/git-http-backend
After that, the error disappeared.
See also my article:
Install Phabricator on Ubuntu