AppVeyor vs Hydra

AppVeyor provides continuous integration tools for Windows developers, with hosted service, self-hosted jobs and an Enterprise installation option for customer premises. A build pipeline can retrieve code, restore caches, install dependencies, build and test software, package artifacts, deploy, then run finalizer scripts. Projects can be configured through an appveyor.yml file or the user interface. Build matrices can create jobs across operating systems, variables, platforms, configurations, test categories and build clouds. Listed source control providers include GitHub, Bitbucket, GitLab, Azure DevOps, Kiln and Gitea. Deployment options include inline providers and environments triggered manually or through the API. The REST API covers teams, projects, builds, environments and deployments, with bearer-token authentication. Secure variables can be encrypted with account-specific keys and are not decoded during pull-request builds by default. Hosted builds use pristine virtual machines not shared with other builds, and VM state is not preserved. Every plan has a 60-minute maximum build-job execution time. Paid plans start at $29 a month.

Hydra is a continuous integration service for projects based on Nix. It checks out project source periodically or continuously, builds it, runs tests, and produces reports. Work is organized into jobsets whose inputs can trigger builds when they change; jobsets can also depend on one another. Flake jobsets are supported when their outputs expose a hydraJobs attribute set. Jobs can produce packages, ISO images, or tarballs, and jobset inputs can use Git checkout sources. Hydra also provides a JSON API. It is aimed at Nix and NixOS package developers, not people who only need to use NixOS. Hydra is open source under GPL-3.0 and listed at free. It is self-hosted, with no hosted option listed, and running it is currently supported only on NixOS; the repository recommends the NixOS module for production. Flake evaluation is restricted from accessing files outside the Nix store. Some state is stored in the database, so backups are needed, and the wiki reports that hydra-queue-runner can sometimes leave queued builds unscheduled.