x/tools/gopls: panic somewhere in a goroutine created by errgroup.Group

[adonovan]

#!stacks
"gopanic" && "errgroup.(*Group).Wait:+6"

Issue created by stacks.

The stack is very unhelpful here since the panic was raised by an errgroup.Group.Go goroutine and all that context is lost due to the errgroup change from proposal #53757. There are at least 7 existing issues that this is potentially a duplicate of--or it may be something new; we cannot tell.

This stack V8TD-Q was reported by telemetry:

• crash/crash
• runtime.gopanic:+69,+0x153
• golang.org/x/sync/errgroup.(*Group).Wait:+6,+0x7b
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).getPackageHandles:+86,+0x2df
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).forEachPackage:+37,+0x523
• golang.org/x/tools/gopls/internal/cache.(*Snapshot).PackageDiagnostics:+28,+0x19b
• golang.org/x/tools/gopls/internal/server.(*server).diagnose.func5:+3,+0x19f
• runtime.goexit:+0,+0x3

golang.org/x/tools/gopls@v0.19.0-pre.3 go1.24.4 darwin/arm64 vscode (1)

Dups: fEn2Cg nHixSg VVj_rg

[gopherbot]

Change https://go.dev/cl/682935 mentions this issue: errgroup: revert propagation of panics

[adonovan]

I broadened this issue to cover the hold class of errgroup issues, which should have been fixed by the reversion of the change in errgroup (CL 682935). I'll update our dependency.