x/tools/gopls: reinitialize the workspace if the module directive changes

[josharian]

I am working to eliminate a fork. The fork includes a change to the module import path. As a consequence, when I change git branches, the module import path changes. This causes gopls to be unable to load the workspace, and as a consequence nothing else works. (This includes saving my document without having to use my mouse to click a Cancel button and not having gofmt run). Once gopls is in this state, the only way I have found to recover is to restart VSCode.

Sample error message:

Error loading workspace: source error list: file:///Users/josh/t/wireguard-go/go.mod:0:0-0:33: go [-e -json -compiled=true -test=true -export=false -deps=true -find=false -- golang.zx2c4.com/wireguard golang.zx2c4.com/wireguard/device]: exit status 1: go: finding module for package github.com/tailscale/wireguard-go/ipc go: finding module for package github.com/tailscale/wireguard-go/wgcfg go: found github.com/tailscale/wireguard-go/ipc in github.com/tailscale/wireguard-go v0.0.20201118 go: golang.zx2c4.com/wireguard/device imports github.com/tailscale/wireguard-go/ipc: github.com/tailscale/wireguard-go@v0.0.20201118: parsing go.mod: module declares its path as: golang.zx2c4.com/wireguard but was required as: github.com/tailscale/wireguard-go

[stamblerre]

Thanks for the report. We should treat a change to the module directive as something that forces a workspace reinitialization.

[stamblerre]

@josharian: Can you share a repro case if you have one available? I saw you mentioned that you had one in your other issue.