nix-fast-build 🚀 (previously known as nix-ci-build)

Combine the power of nix-eval-jobs with nix-output-monitor to speed-up your evaluation and building process. nix-fast-build an also integrates with remote machines by uploading the current flake, performing the evaluation/build remotely, and then transferring the resultant store paths back to you.

Why nix-fast-build?

Problem: Evaluating and building big flakes i.e. with numerous NixOS machines can be painfully slow. For instance, rebuilding the already-compiled disko integration test suite demands 1:50 minutes on an AMD Ryzen 9 7950X3D. But, it only takes a 10 seconds with nix-fast-build.

Solution: nix-fast-build makes builds faster by evaluating and building building your nix packages concurrently, reducing the overall time.

How Does It Work?

Under the hood:

1. It leverages the output from nix-eval-jobs to evaluate flake attributes in parallel.
2. As soon as attributes complete evaluation, nix-fast-build initiates their build, even if the overall evaluation is ongoing.
3. Lastly, nix-output-monitor to show the build progress nicely.
4. (Optional) Once a build finishes, nix-fast-build can initiate its upload to a designated remote binary cache.

Usage

To get started, run:

$ nix-fast-build

or:

$ nix run github:Mic92/nix-fast-build

This command will concurrently evaluate and build the attributes .#checks.$currentSystem.

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Enjoy faster and more efficient NixOS builds with nix-fast-build!

Remote building

When leveraging the remote-builder protocol, uploading pre-built paths or sources from the local machine can often turn into a bottleneck. nix-fast-build does not use the remote-builder protocol. Instead it uploads only the flake and executes all evaluation/build operations on the remote end. At the end nix-fast-build will download the finished builds to the local machine while not having to download all build dependencies in between.

Here is how to use it:

nix run github:Mic92/nix-ci-build -- --remote youruser@yoursshhostname

Replace youruser@yoursshhostname with your SSH login credentials for the target machine. Please note that as of now, you must be recognized as a trusted user on the remote endpoint to access this feature.

Reference

usage: nix-fast-build [-h] [-f FLAKE] [-j MAX_JOBS] [--option name value] [--no-nom] [--systems SYSTEMS]
                    [--retries RETRIES] [--remote REMOTE] [--always-upload-source] [--no-download]
                    [--skip-cached] [--copy-to COPY_TO] [--verbose]
                    [--eval-max-memory-size EVAL_MAX_MEMORY_SIZE] [--eval-workers EVAL_WORKERS]

options:
  -h, --help            show this help message and exit
  -f FLAKE, --flake FLAKE
                        Flake url to evaluate/build (default: .#checks
  -j MAX_JOBS, --max-jobs MAX_JOBS
                        Maximum number of build jobs to run in parallel (0 for unlimited)
  --option name value   Nix option to set
  --no-nom              Use nix-output-monitor to print build output (default: false)
  --systems SYSTEMS     Comma-separated list of systems to build for (default: current system)
  --retries RETRIES     Number of times to retry failed builds
  --remote REMOTE       Remote machine to build on
  --always-upload-source
                        Always upload sources to remote machine. This is needed if the remote machine cannot
                        access all sources (default: false)
  --no-download         Do not download build results from remote machine
  --skip-cached         Skip builds that are already present in the binary cache (default: false)
  --copy-to COPY_TO     Copy build results to the given path (passed to nix copy, i.e.
                        file:///tmp/cache?compression=none)
  --verbose             Print verbose output
  --eval-max-memory-size EVAL_MAX_MEMORY_SIZE
                        Maximum memory size for nix-eval-jobs (in MiB) per worker. After the limit is
                        reached, the worker is restarted.
  --eval-workers EVAL_WORKERS
                        Number of evaluation threads spawned