I set up a small(er) reproduction of what I saw in this repo: https://github.com/danp/go-40456. Note this is not using vendoring as the project I mentioned in Slack is.

The main branch starts with k8s.io/client-go at v0.0.0-20190802021151-fdb3fbe99e1d and the change branch updates it to v0.18.6. The change branch also changes main.go to add the initial context.Context argument to List that v0.18.6 expects.

On changing from main to change, the call to List is highlighted with an error as if gopls/etc still expect the first (and only) arg to List to be a metav1.ListOptions.

Log from gopls with -rpc.trace attached. 09:08:xx is loading up main.go on the main branch, the entries beginning at 09:09:10.407 are when I changed to the change branch and the error appeared.

Thank you so much for the repro case! We'll take a look.

Change https://golang.org/cl/245779 mentions this issue: internal/lsp: invalidate all packages on go.mod file changes

(Please let me know if you'd prefer this feedback on the CL)

I gave https://golang.org/cl/245779 a try with my repro and I'm still seeing the same behavior. Was wondering if it somehow relied on me having go.mod open but that didn't seem to matter. Added some quick logging around here to see what currentFH values appear and it was only ever related to main.go (with Kind == source.Go).

I remember you had mentioned on Slack that you disabled file watching in some cases? You will need it enabled for your client to send gopls notifications when you switch branches. The problem no longer reproduces for me in your repro when using VS Code.

It's correct that I had been disabling file watching for the original project I saw this in. Since it uses vendoring there are many files so I get the prompt asking whether I want to watch them all.

However, the reproduction project is much smaller and (I think) everything is watched by default as I'm not prompted. The testing/logging/etc I did above was done in the reproduction project.

Digging and debugging more, it's now looking like this has uncovered an issue in lsp-mode. It doesn't seem to be liking the glob change originally made in golang/tools@fd294ab. After changing GlobPattern back to **.go and adding a second FileSystemWatcher for **.mod, I'm getting the lsp-mode and gopls debug logging I expect.

Will open an lsp-mode issue for the globbing trouble. Thanks!