Logging from `initialize`

Stream: lean4

[Eric Wieser]

Is it possible to log warnings from initialize? As far as I can tell this always runs in IO, and my foolish attempt to log with IO.println results in the Lean vscode extension hanging, presumably due to malformed output from the server.

[𝚠𝚘𝚓𝚌𝚒𝚎𝚌𝚑 𝚗𝚊𝚠𝚛𝚘𝚌𝚔𝚒]

IO.eprintln! (Server stdout goes to LSP, whereas stderr is forwarded to the editor output window.)