client-gen generates empty files when using Go 1.23

[JRBANCEL]

We use client-gen like this:

client-gen \
        --input-base "github.com/<WHATEVER>/pkg/apis" \
        --input "dedicated/v1alpha1" \
        --output-pkg github.com/<WHATEVER>/pkg/clientset \
        --go-header-file hack/header.txt \
        --clientset-name versioned \
        --output-dir ./pkg/clientset

Works fine in 1.22.0 (and v0.30.1).

Now, when I bump go.mod to use 1.23.0, client-gen generates files with just the package statement:

// Code generated by client-gen. DO NOT EDIT.

package v1alpha1

Output with -v 10 doesn't show anything interesting.
I tried to update client-gen to v0.31.0, same result.

[Airblader]

Several people in my team have the same issue with tooling like deepcopy-gen. Oddly, though, for me it seems to work.

[luca-filipponi]

@JRBANCEL try to clean the go mod cache go clean -modcache, this worked for us

[zaininHub]

go mod cache clean doesnt help, has any solution else?

[dpeckett]

What's happening here is that code-generator needs to built with the same major.minor version of Go as your project (due to the way it hooks into the go toolchain). If you use go install or go run it will automatically downgrade to the toolchain version in the code-generator go.mod.

To fix this, just export GOTOOLCHAIN=go1.23.3 or whatever version is appropriate before running go install / go run.