Updated my flake two days ago and again today (using unstable) and I’m getting an error when trying to rebuild. I can’t figure out why it can’t build udevil because I didn’t add any new packages and from looking at Nix Package Versions it seems udevil is in 0.4.4 for a long time, so any packages I already had that rebuilt just fine before shouldn’t be triggering this. Should I submit an issue or can I resolve this another way?
My dotfiles are here and the only change besides updating my flake that I’ve done is adding .local/bin to my PATH, though I haven’t pushed the updated lock file yet. Removed the PATH change and still didn’t rebuild. Below is the error output. Same thing happens when attempting to rebuild with nh.
❯ sudo nixos-rebuild switch --flake .
building the system configuration...
trace: evaluation warning: The syntax of services.swayidle.events has changed. While it
previously accepted a list of events, it now accepts an attrset
keyed by the event name.
error: builder for '/nix/store/8fq9pa3ql2zhhbfvhxgb2pw1j62cq8rd-udevil-0.4.4.drv' failed with exit code 2;
last 25 log lines:
> | ^~~~~~~~~~~~~~~~~
> udevil.c:2245:9: warning: ignoring return value of 'setreuid' declared with attribute '8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attributewarn_unused_result8;;' [8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Warning-Options.html#index-Wno-unused-result-Wunused-result8;;]
> 2245 | setreuid( orig_ruid, -1 );
> | ^~~~~~~~~~~~~~~~~~~~~~~~~
> udevil.c:2246:9: warning: ignoring return value of 'setregid' declared with attribute '8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attributewarn_unused_result8;;' [8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Warning-Options.html#index-Wno-unused-result-Wunused-result8;;]
> 2246 | setregid( orig_rgid, -1 );
> | ^~~~~~~~~~~~~~~~~~~~~~~~~
> udevil.c: In function 'exec_program':
> udevil.c:2016:9: warning: ignoring return value of 'setreuid' declared with attribute '8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attributewarn_unused_result8;;' [8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Warning-Options.html#index-Wno-unused-result-Wunused-result8;;]
> 2016 | setreuid( 0, -1 ); // mount needs real uid
> | ^~~~~~~~~~~~~~~~~
> udevil.c:2017:9: warning: ignoring return value of 'setregid' declared with attribute '8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attributewarn_unused_result8;;' [8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Warning-Options.html#index-Wno-unused-result-Wunused-result8;;]
> 2017 | setregid( 0, -1 );
> | ^~~~~~~~~~~~~~~~~
> udevil.c:2035:9: warning: ignoring return value of 'setreuid' declared with attribute '8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attributewarn_unused_result8;;' [8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Warning-Options.html#index-Wno-unused-result-Wunused-result8;;]
> 2035 | setreuid( orig_ruid, -1 );
> | ^~~~~~~~~~~~~~~~~~~~~~~~~
> udevil.c:2036:9: warning: ignoring return value of 'setregid' declared with attribute '8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attributewarn_unused_result8;;' [8;;https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Warning-Options.html#index-Wno-unused-result-Wunused-result8;;]
> 2036 | setregid( orig_rgid, -1 );
> | ^~~~~~~~~~~~~~~~~~~~~~~~~
> make[2]: *** [Makefile:485: udevil-udevil.o] Error 1
> make[2]: Leaving directory '/build/source/src'
> make[1]: *** [Makefile:428: all-recursive] Error 1
> make[1]: Leaving directory '/build/source'
> make: *** [Makefile:359: all] Error 2
For full logs, run 'nix log /nix/store/8fq9pa3ql2zhhbfvhxgb2pw1j62cq8rd-udevil-0.4.4.drv'.
error: 1 dependencies of derivation '/nix/store/2k2s714z8phj18d09yli0gvbm3bnmg07-unit-devmon.service.drv' failed to build
error: 1 dependencies of derivation '/nix/store/7hj7j5ras8q6vvbx6ffmfrkw74c4vpbr-user-units.drv' failed to build
error: 1 dependencies of derivation '/nix/store/rvkzfj5lf1f0ffd9cb313jrvslyargby-etc.drv' failed to build
error: 1 dependencies of derivation '/nix/store/rg4xyv89rg2dpkf3rzgif5mdpg65vgfd-nixos-system-desktop-26.05.20251230.cad22e7.drv' failed to build
Command 'nix --extra-experimental-features 'nix-command flakes' build --print-out-paths '.#nixosConfigurations."desktop".config.system.build.toplevel' --no-link' returned non-zero exit status 1.