nixd dies on shutdown but not in the way eglot expects? about nixd HOT 2 CLOSED

There are merely two problems reported in this issue, the first:

I[15:06:47.126] 249743: --> notify exit
V[15:06:47.126] 249743: >>> {"jsonrpc":"2.0","method":"exit","params":null}
I[15:06:47.158] 249743: --> notify exit
V[15:06:47.158] 249743: >>> {"jsonrpc":"2.0","method":"exit","params":null}

These two "exit" requests is sent by our server to eval providers (one for nixpkgs, another for an options system) and are expected. And I wrote these requests in the source code, to make the workers clean the resources.

In nixd, these eval providers are used for interoperating with C++ nix, these workers directly links with C++ nix libraries, effectively the nix-repl exposed by an RPC protocol.

the second:

eglot complains that the LSP died:

I don't know what's the reason exactly, if it does not bother you, can we leave this as-is?

from nixd.

if it does not bother you, can we leave this as-is?

The problem is that the server not shutting down "cleanly" has knock-on effects. Eglot has a function to shutdown the server when the last LSP-managed buffer of a project is killed. When the server doesn't shut down cleanly, it (rightfully) complains and aborts killing the buffer which is annoying to deal with; especially when killing multiple projects at once.

I am not familiar with the LSP spec in the slightest. Since you are, do you have a hunch what might be going wrong here?

Is there any way to get more debug info from the nixd side?

from nixd.