Nixpkgs version

• Stable (25.05)

Describe the bug

Tailscale package fails to build on NixOS 25.05 due to test failures in the portlist module. Tests fail with "seek /proc/net/tcp: illegal seek" error during the build process.

NixOS normally uses pre-built binaries from cache, not source compilation for tailscale

Steps to reproduce

On NixOS 25.05 (nixos-25.05 channel)
Add services.tailscale.enable = true; to /etc/nixos/configuration.nix
Run sudo nixos-rebuild switch
Build fails during tailscale package compilation

Expected behaviour

Tailscale package should build successfully and install without test failures.

Screenshots

No response

Relevant log output

--- FAIL: TestGetList (0.00s)
    portlist_test.go:19: seek /proc/net/tcp: illegal seek
--- FAIL: TestIgnoreLocallyBoundPorts (0.00s)
    portlist_test.go:40: seek /proc/net/tcp: illegal seek
--- FAIL: TestPoller (0.00s)
    portlist_test.go:61: seek /proc/net/tcp: illegal seek
FAIL
FAIL    tailscale.com/portlist  0.006s
FAIL
error: builder for '/nix/store/18r5bq5bx8n79mgpv69mnfjq8w7z05b0-tailscale-1.82.5.drv' failed with exit code 1

Additional context

• NixOS 25.05 (nixos-25.05 channel)
• Kernel: Linux 6.12.44
• Architecture: x86_64
• Tailscale version: 1.82.5
• Channel updated: 2025-08-30

System metadata

• system: "x86_64-linux"
• host os: Linux 6.12.44, NixOS, 25.05 (Warbler), 25.05.809091.41d292bfc373
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.28.4
• channels(root): "nixos-25.05"
• nixpkgs: /nix/store/plvncw7nnh8bjznhqh1vhkfjiql4n6w2-nixos-25.05/nixos

Notify maintainers

@martinbaillie @06kellyjac @mfrw @pyrox0 @ryan4yin

Note for maintainers: Please tag this issue in your pull request description. (i.e. Resolves #ISSUE.)

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