Cannot update NixOS because library fails to compile

Help
1

nix-flake-tests 3.6.1 fails to compile, preventing an update for my system:

➜  sudo nixos-rebuild switch --flake .#
[sudo] contraseña para jorge:
error: builder for '/nix/store/9ikp93w7ipazyxkcfmj5268mlbh8yhfm-nix-flake-tests-3.6.1.drv' failed with exit code 1;
       last 25 log lines:
       > mesonConfigurePhase flags: --prefix=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1 --libdir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/lib --libexecdir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/libexec --bindir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/bin --sbindir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/sbin --includedir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/include --mandir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/share/man --infodir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/share/info --localedir=/nix/store/hgc33l8w43bgv98sl6bwy2h5562rsfll-nix-flake-tests-3.6.1/share/locale -Dauto_features=enabled -Dwrap_mode=nodownload --buildtype=release -Db_lto=true
       > The Meson build system
       > Version: 1.7.2
       > Source dir: /build/source/src/libflake-tests
       > Build dir: /build/source/src/libflake-tests/build
       > Build type: native build
       > Project name: nix-flake-tests
       > Project version: 2.29.0
       > C++ compiler for the host machine: g++ (gcc 14.2.1 "g++ (GCC) 14.2.1 20250322")
       > C++ linker for the host machine: g++ ld.bfd 2.44
       > Host machine cpu family: x86_64
       > Host machine cpu: x86_64
       > Found pkg-config: YES (/nix/store/nbph466agczbny52jzk143ydcp2x14q4-pkg-config-wrapper-0.29.2/bin/pkg-config) 0.29.2
       > Did not find CMake 'cmake'
       > Found CMake: NO
       > Run-time dependency nix-expr-test-support found: NO
       >
       > meson.build:18:2: ERROR: Dependency lookup for nix-expr-test-support with method 'pkgconfig' failed: Could not generate cflags for nix-expr-test-support:
       > Package nix-util was not found in the pkg-config search path.
       > Perhaps you should add the directory containing `nix-util.pc'
       > to the PKG_CONFIG_PATH environment variable
       > Package 'nix-util', required by 'nix-expr-test-support', not found
       >
       >
       > A full log can be found at /build/source/src/libflake-tests/build/meson-logs/meson-log.txt
       For full logs, run:
         nix log /nix/store/9ikp93w7ipazyxkcfmj5268mlbh8yhfm-nix-flake-tests-3.6.1.drv
error: 1 dependencies of derivation '/nix/store/pqg1isjznai2n2k93b701cwjqgjn30mv-nix-flake-tests-run.drv' failed to build
error: 1 dependencies of derivation '/nix/store/r2i455qc78f2nvs1i5adamvnpl33was1-determinate-nix-3.6.1.drv' failed to build
error: 1 dependencies of derivation '/nix/store/vv836qx97rnrpyib9vhsav7zs766brv4-nixos-rebuild.drv' failed to build
2

You’re using an unofficial nix fork; presumably from a third flake input. Looks like its build isn’t updated to work with the 25.05 nixpkgs yet or something. Consider using at least a nix packaged in nixpkgs, since those will be tested and built with the rest of your distro.

3

Might as well report it here too:

3 Likes
4

the problem was an input’s module

inputs = { determinate.url = "https://flakehub.com/f/DeterminateSystems/determinate/*"; }

Removing it for now allows me to update my system