gopls: investigate why we still see many empty gopls automated issue reports

[hyangah]

My guess is a race condition - gopls trace output window should be shown before the automated issue report logic can read and process the output. But there could be other issues such as unexpected output formats. Investigate and improve the robustness.

[gopherbot]

Change https://golang.org/cl/274449 mentions this issue: src/goLanguageServer: improve automated gopls log collection

[gopherbot]

Change https://golang.org/cl/276553 mentions this issue: [release] src/goLanguageServer: improve automated gopls log collection