Building p4-fusion

In order to import Perforce depots into Sourcegraph we first convert them into git repositories. We use an open source tool called p4-fusion:

A fast Perforce depot to Git repository converter using the Helix Core C/C++ API as an attempt to mitigate the performance bottlenecks in git-p4.py.

Building p4-fusion can be a little tricky as it depends on some older libraries and also doesn't build on M1 Apple laptops. To get around this we use nix.

How to build

Below are the instructions for building p4-fusion locally, assuming you have the Sourcegraph repository checked out.

1. Follow these instruction to install Nix. (Tested with version 2.11.1)
2. Navigate to the root of your Sourcegraph directory
3. Run nix build ".#p4-fusion" --verbose --extra-experimental-features nix-command --extra-experimental-features flakes

If the build completes successfully you should have a p4-fusion binary in ./result/bin/p4-fusion which you can copy somewhere in your $PATH