Switching to unstable errors

I have a config that works on the 24.05 channel. I use zen browser and it’s been out of date for a while so I’m trying to update it. I used to use this in my flake GitHub - MarceColl/zen-browser-flake: Nix Flake for the Zen Browser to install it, but when I asked in discord about how to update it someone told me to switch to this GitHub - 0xc000022070/zen-browser-flake: Community-driven Nix Flake for the Zen browser. I tried and got the error that libgbm is undefined. I changed the channel in my flake to unstable and then tried to rebuild and that’s when I got this error.

building the system configuration...
error: builder for '/nix/store/cm5nl0hp9dq3sm5f45pqcqz2ksxpz2x8-expressvpn-3.52.0.2.drv' failed with exit code 1;
       last 9 log lines:
       > Running phase: patchPhase
       > Running phase: updateAutotoolsGnuConfigScriptsPhase
       > Running phase: installPhase
       > Running phase: fixupPhase
       > shrinking RPATHs of ELF executables and libraries in /nix/store/7sa7vxmz980nyrmbyy1j00j1awnmkpvj-expressvpn-3.52.0.2
       > checking for references to /build/ in /nix/store/7sa7vxmz980nyrmbyy1j00j1awnmkpvj-expressvpn-3.52.0.2...
       > patching script interpreter paths in /nix/store/7sa7vxmz980nyrmbyy1j00j1awnmkpvj-expressvpn-3.52.0.2
       > ERROR: noBrokenSymlinks: the symlink /nix/store/7sa7vxmz980nyrmbyy1j00j1awnmkpvj-expressvpn-3.52.0.2/bin/expressvpnd points to a missing target: /nix/store/70m25q6a70cscgi5pcf9xcapzg6k5sdx-expressvpn-3.52.0.2/bin/expressvpnd
       > ERROR: noBrokenSymlinks: found 1 dangling symlinks and 0 reflexive symlinks
       For full logs, run 'nix log /nix/store/cm5nl0hp9dq3sm5f45pqcqz2ksxpz2x8-expressvpn-3.52.0.2.drv'.
error (ignored): error: cannot unlink '"/tmp/nix-build-turbo-unwrapped-2.4.2.drv-8/build/turbo-unwrapped-2.4.2-vendor"': Directory not empty
error (ignored): error: cannot unlink '"/tmp/nix-build-modrinth-app-unwrapped-pnpm-deps.drv-4/build/source/node_modules/.pnpm/typescript@5.5.4/node_modules/typescript_tmp_79/lib"': Directory not empty
error (ignored): error: cannot unlink '"/tmp/nix-build-icu4c-75.1.drv-2/build/icu/source"': Directory not empty
error (ignored): error: cannot unlink '"/tmp/nix-build-libdbusmenu-gtk2-16.04.0.drv-0/build/libdbusmenu-16.04.0"': Directory not empty
error (ignored): error: cannot unlink '"/tmp/nix-build-curl-8.12.1.drv-2/build/curl-8.12.1"': Directory not empty
error (ignored): error: cannot unlink '"/tmp/nix-build-SDL2_ttf-2.24.0.drv-0/build/SDL2_ttf-2.24.0"': Directory not empty
error (ignored): error: cannot unlink '"/tmp/nix-build-timidity-2.15.0.drv-1/build/TiMidity++-2.15.0"': Directory not empty
error (ignored): error: cannot unlink '"/tmp/nix-build-smpeg2-unstable-2022-05-26.drv-0/build"': Directory not empty
error: 1 dependencies of derivation '/nix/store/09q8900zi2vvbl24jdmxkaa94kw66nxp-system-path.drv' failed to build
error (ignored): error: cannot unlink '"/tmp/nix-build-nvidia-x11-570.124.04-6.12.19.drv-5/build/NVIDIA-Linux-x86_64-570.124.04/kernel"': Directory not empty
error: 1 dependencies of derivation '/nix/store/r966r6hapxar61d1wlsdm7a6pfakqhbb-unit-expressvpn.service.drv' failed to build
error: 1 dependencies of derivation '/nix/store/msc7yikqf7w3sz9vdiavizqwv1lnk2zr-nixos-system-nixos-25.05.20250318.b6eaf97.drv' failed to build

Here’s my nix-info

system: "x86_64-linux", multi-user?: yes, version: nix-env (Nix) 2.24.10, channels(root): "home-manager, nixos", nixpkgs: /nix/store/w66xaybnxjf5zhxapxs3pd3zp7gxk9dw-source```

Per your logs expressvpn fails to build, report it to nixpkgs.

How do I make it build without expressvpn? Even if I remove it from my configuration.nix I get the same errors

That’s impossible, expressvpn would only be in your config if you add it or something that depends on it.