# New version of tailscale has NixOS issues. ## Tailscale fails to build from source on NixOS 25.05 due to test failures with the error: "seek /proc/net/tcp: illegal seek" This affects kernel 6.12.34+ and is tracked in [NixOS/nixpkgs#438765](https://github.com/NixOS/nixpkgs/issues/438765). `tailscale-workaround.nix`: ```nix { config, pkgs, lib, ... }: let tailscale-static = pkgs.stdenv.mkDerivation rec { pname = "tailscale"; version = "1.86.2"; src = pkgs.fetchurl { url = "https://pkgs.tailscale.com/stable/tailscale_${version}_amd64.tgz"; sha256 = "sha256-OxItnx+/KBzzx5/WHoTImvmjZHxGSFnL7o8TP/p06Pg="; }; installPhase = '' mkdir -p $out/bin cp tailscale tailscaled $out/bin/ chmod +x $out/bin/* ''; dontBuild = true; dontStrip = true; dontPatchELF = true; dontFixup = true; }; in { services.tailscale = { enable = true; package = tailscale-static; }; systemd.services.tailscaled = { serviceConfig = { ExecStart = "${tailscale-static}/bin/tailscaled --state=/var/lib/tailscale/tailscaled.state --socket=/run/tailscale/tailscaled.sock"; }; path = [ pkgs.iproute2 pkgs.iptables ]; }; } ``` **Instructions for users:** # Tailscale NixOS 25.05 Workaround This fixes the Tailscale build failure on NixOS 25.05 with kernel 6.12.34+. maybe other kernel versions, but I've seen it on .34, .42 and .44. It also affects running systems with --upgrade ## Installation 1. Save the module as `/etc/nixos/tailscale-workaround.nix` 2. Add to your `/etc/nixos/configuration.nix`: ## What this does Uses Tailscale's prebuilt static binary instead of compiling from source, avoiding the test failures on newer kernels. # Tailscale NixOS 25.05 Workaround This fixes the Tailscale build failure on NixOS 25.05 with kernel 6.12.44+. ## Installation 1. Save the module as `/etc/nixos/tailscale-workaround.nix` 2. Add to your `/etc/nixos/configuration.nix`: ```nix imports = [ ./tailscale-workaround.nix ]; ``` 3. Rebuild: `sudo nixos-rebuild switch` 4. Start Tailscale: `sudo tailscale up` ## What this does Uses Tailscale's prebuilt static binary instead of compiling from source, avoiding the test failures on newer kernels.