Signature help and nullable option: `assert false`

[crackcomm]

I'm using ray-x/lsp_signature.nvim signature in neovim and signature help keeps throwing exceptions in seemingly random places, mostly ;; and empty lines. It displays correct signature help otherwise.

Nullable_option.yojson_of_t has an assert false statement for the None case.

[DEBUG][2025-05-02 09:46:58] .../vim/lsp/rpc.lua:277	"rpc.send"	{ id = 46, jsonrpc = "2.0", method = "textDocument/signatureHelp", params = { position = { character = 2, line = 82 }, textDocument = { uri = "file:///home/pah/x/monorepo-ocxmr/ocaml/bazel/bazel.ml" } } }
[DEBUG][2025-05-02 09:46:58] .../vim/lsp/rpc.lua:391	"rpc.receive"	{ jsonrpc = "2.0", method = "textDocument/publishDiagnostics", params = { diagnostics = {}, uri = "file:///home/pah/x/monorepo-ocxmr/ocaml/bazel/bazel.ml" } }
[TRACE][2025-05-02 09:46:58] ...m/lsp/client.lua:1105	"notification"	"textDocument/publishDiagnostics"	{ diagnostics = {}, uri = "file:///home/pah/x/monorepo-ocxmr/ocaml/bazel/bazel.ml" }
[TRACE][2025-05-02 09:46:58] ...lsp/handlers.lua:656	"default_handler"	"textDocument/publishDiagnostics"	{ ctx = '{\n  client_id = 2,\n  method = "textDocument/publishDiagnostics"\n}', result = { diagnostics = {}, uri = "file:///home/pah/x/monorepo-ocxmr/ocaml/bazel/bazel.ml" } }
[DEBUG][2025-05-02 09:46:58] .../vim/lsp/rpc.lua:391	"rpc.receive"	{ error = { code = -32603, data = { backtrace = 'Raised at Lsp__Import.Json.Nullable_option.yojson_of_t in file "lsp/src/import.ml", line 219, characters 16-28\nCalled from Lsp__Types.SignatureHelp.yojson_of_t in file "lsp/src/types.ml", lines 49237-49239, characters 13-32\nCalled from Lsp_fiber__Rpc.Make.to_jsonrpc.on_request.to_response in file "lsp-fiber/src/rpc.ml", line 184, characters 37-70\nCalled from Lsp_fiber__Rpc.Make.to_jsonrpc.on_request.f.(fun) in file "lsp-fiber/src/rpc.ml", line 196, characters 37-52\nCalled from Fiber__Scheduler.exec in file "fiber/src/scheduler.ml", line 73, characters 8-11\nRe-raised at Stdune__Exn.raise_with_backtrace in file "otherlibs/stdune/src/exn.ml" (inlined), line 38, characters 27-56\nCalled from Stdune__Exn_with_backtrace.reraise in file "otherlibs/stdune/src/exn_with_backtrace.ml", line 20, characters 33-71\nCalled from Fiber__Scheduler.exec in file "fiber/src/scheduler.ml", line 73, characters 8-11\n', exn = 'File "lsp/src/import.ml", line 219, characters 16-22: Assertion failed' }, message = "uncaught exception" }, id = 46, jsonrpc = "2.0" }

I'm on 1.2.1 revision.