<![CDATA[The Nix sandbox aims to provide a pure environment by isolating the build environment from the rest of the system.]]>The Nix sandbox aims to provide a pure environment by isolating the build environment from the rest of the system. However, some impurities can still affect builds inside the sandbox and lead to reproducibility issues. One of them is the filesystem.

A common example is builds that implicitly depend on inode numbering or directory entry ordering. In some cases, you might even run into a filesystem bug: a build succeeds on one machine, but fails on another with a different filesystem.

To debug these issues, you can now use nix-buildon. It lets you swap out the filesystem underneath the Nix sandbox. By running the sandbox on disorderfs, you can get a deterministic, sorted, or reverse-sorted view of directory entries. This makes it easy to check whether a build depends on filesystem behavior that should not matter in the first place.

Link Preview Image
GitHub - katexochen/nix-buildon: Discover filesystem-based reproducibility issues by running the Nix sandbox on different filesystems

Discover filesystem-based reproducibility issues by running the Nix sandbox on different filesystems - katexochen/nix-buildon

favicon

GitHub (github.com)

I created this at . 🌊

]]>https://board.circlewithadot.net/topic/05f37f05-c3be-4897-9a12-05189645fdec/the-nix-sandbox-aims-to-provide-a-pure-environment-by-isolating-the-build-environment-from-the-rest-of-the-system.RSS for NodeThu, 14 May 2026 20:51:23 GMTSat, 18 Apr 2026 13:02:59 GMT60