`go-generate` fails on `GOPATH is not set`

[rdeknijf]

go-generate doesn't work

$ pants go-generate ::

13:56:18.02 [INFO] Completed: Process `go generate` directives in file: pkg/something.go
13:56:18.02 [ERROR] 1 Exception encountered:

Engine traceback:
in `go-generate` goal

ProcessExecutionFailure: Process 'Process `go generate` directives in file: pkg/something.go' failed with exit code 1.
stdout:

stderr:
2024/10/09 13:56:18 Loading input failed: GOPATH is not set

Use `--keep-sandboxes=on_failure` to preserve the process chroot for inspection.

Pants version Tested 2.22, 2.21 and 2.23

OS Both Linux and Mac

Small reproduction repo https://github.com/rdeknijf/pants-repro-gogen