`nix flake update` is failing (probably) because Google

This has never been a problem before today. I am in China. I cannot use Google. When I ran nix flake update today, it threw an error:

Builderror: builder for '/nix/store/g1am2vaz0mrkn62qk0hd6asbf1h4a4yn-hugo-0.138.0-go-modules.drv' failed with exit code 1;
       last 8 log lines:
       > Running phase: unpackPhase
       > unpacking source archive /nix/store/x6cnq1q2xr7r0l48bffvb194dzi315gb-source
       > source root is source
       > Running phase: patchPhase
       > Running phase: updateAutotoolsGnuConfigScriptsPhase
       > Running phase: configurePhase
       > Running phase: buildPhase
       > go: cloud.google.com/go@v0.115.0: Get "https://proxy.golang.org/cloud.google.com/go/@v/v0.115.0.mod": dial tcp 142.250.217.81:443: i/o timeout
error: 1 dependencies of derivation '/nix/store/fjjj461n08zkf7wvqrgyvh91qq1ympn9-hugo-0.138.0.drv' failed to build
error: 1 dependencies of derivation '/nix/store/iy8m5xq1lblsbp600hnw3v11wslmyqwk-home-manager-path.drv' failed to build
error: 1 dependencies of derivation '/nix/store/6rwlakkzyz0hd5kvma51s7vjw1ifv6j9-hugo-0.138.0-fish-completions.drv' failed to build
error: 1 dependencies of derivation '/nix/store/g8jlzkgws2vbzvk9id5ks86xjs4bl13k-man-paths.drv' failed to build
error: 1 dependencies of derivation '/nix/store/mnxxdpgz8q9lklm29nym0qcpm8jbfr3z-home-manager-generation.drv' failed to build

It seems clear that’s because it’s trying to go to Google, which it presumably never did before.

How do I fix this?

What is your Nixpkgs input set to point at in your flake and are you using Linux or macOS?

(You should generally never have to “wait for Hydra”; the channels only update when all their constituent builds are finished, so if you’re tracking the right Nixpkgs branch, things like this usually only happen because something is failing on Hydra or you have overlays messing things up.)

Right. In that case my suggestion would be “use nixos-unstable:slight_smile:

Ah. I had forgotten that I had changed my nixpkgs.url to tsinghua because I am in China and couldn’t figure out how to make the substituter pick tsinghua (that has been resolved). Switching that back to the default unstable url fixed it. Thanks for the help.

Linux, btw.