gopackagesdriver does not work in pure GOWORK mode in a monorepo

[mikn]

We're using a go.work layout in a monorepo, and setting gopackagesdriver in VSCode using it with gopls, results in a query to the gopackagesdriver that is only ./... builtin - this does not resolve any modules from the go.work file, nor finds any go.mod files within the workspace.

It results in the very unintuitive Error message in VSCode:

[Error - 12:30:22] 2025/02/05 12:30:21 go/packages.Load #1: unexpected end of JSON input
	view_id="1"
	snapshot=0
	directory=/home/mikn/src
	query=[./... builtin]
	packages=0
	duration=688.341518ms

[Error - 12:30:22] 2025/02/05 12:30:21 initial workspace load failed: packages.Load error: unexpected end of JSON input

The error was figured out by looking at what the query field is set to when not using an external GOPACKAGESDRIVER, which, to go list is expanded to each module defined in the go.work file.

We fixed this for now, by doing this:

#!/usr/bin/env bash

if [[ -f "go.work" ]]; then
  new_args=()
  for arg in "${@}"; do
    if [[ "$arg" == "./..." ]]; then
      new_args+=($(go list -m -f '{{.Path}}' | xargs -I {} echo {}/...))
    else
      new_args+=("$arg")
    fi
  done
  set -- "${new_args[@]}"
fi
exec bazel run -- @rules_go//go/tools/gopackagesdriver "${@}"

I am not sure this is a bug with the rules_go gopackagesdriver, or if it is gopls that is sending the wrong query in external mode, but we decided to fix it in the gopackagesdriver wrapper as it was the easiest place for us and I suspect that it may be the easiest to fix in rules_go also.