Pipe your nix-build output through the nix-output-monitor a.k.a nom to get additional information while building.
nix-output-monitor (nom) is a tool that enriches the output of nix build commands by piping their logs through an additional monitor layer to display real-time build progress, dependency trees, and timing information. The project is written in Haskell and works with both legacy nix v1 commands like nix-build and modern nix v2 commands like nix build and nix shell. Maintained by an individual developer (maralorn), nom parses nix build output in JSON or human-readable formats and displays build status using color-coded symbols, durations, and a visual dependency graph to help users track build progress more effectively.