We have used ViewVC as our repository browser. It is great and the ViewVC view of the webfaction cloudy repository is at
Web searches turn up lots of examples of installing ViewVC with apt-get on Ubuntu 14 and before. The package is not available on U20. That leaves the project website and tarball.
The install file for the current release version, 1.2, lists the prerequisites
It does not support Python 3:
So, similar to trac.
The Unreleased bleeding edge (1.3-dev) does support 3:
so, not quite as bad as trac, if we want to live on the bleeding edge.
GitLab and tools built into git provide this same functionality, I believe.