Error when buffer is not visiting a file

[akash-akya]

• Server used: ElixirLS
• Emacs version: GNU Emacs 29.0.50
• Operating system: mac osx
• Eglot version: 57779f9
• Eglot installation method: git
• Using Doom: No

ElixisLS - M-x eglot-events-buffer

[internal] Tue Jan 25 22:22:26 2022:
(:message "Running language server: (/Users/akash/elixir-ls/language_server.sh)")
[client-request] (id:1) Tue Jan 25 22:22:26 2022:
(:jsonrpc "2.0" :id 1 :method "initialize" :params
          (:processId 17933 :rootPath "/Users/akash/rhea/" :rootUri "file:///Users/akash/rhea" :initializationOptions #s(hash-table size 65 test eql rehash-size 1.5 rehash-threshold 0.8125 data
                                                                                                                                                                ())
                      :capabilities
                      (:workspace
                       (:applyEdit t :executeCommand
                                   (:dynamicRegistration :json-false)
                                   :workspaceEdit
                                   (:documentChanges :json-false)
                                   :didChangeWatchedFiles
                                   (:dynamicRegistration t)
                                   :symbol
                                   (:dynamicRegistration :json-false)
                                   :configuration t)
                       :textDocument
                       (:synchronization
                        (:dynamicRegistration :json-false :willSave t :willSaveWaitUntil t :didSave t)
                        :completion
                        (:dynamicRegistration :json-false :completionItem
                                              (:snippetSupport t :deprecatedSupport t :tagSupport
                                                               (:valueSet
                                                                [1]))
                                              :contextSupport t)
                        :hover
                        (:dynamicRegistration :json-false :contentFormat
                                              ["markdown" "plaintext"])
                        :signatureHelp
                        (:dynamicRegistration :json-false :signatureInformation
                                              (:parameterInformation
                                               (:labelOffsetSupport t)
                                               :activeParameterSupport t))
                        :references
                        (:dynamicRegistration :json-false)
                        :definition
                        (:dynamicRegistration :json-false :linkSupport t)
                        :declaration
                        (:dynamicRegistration :json-false :linkSupport t)
                        :implementation
                        (:dynamicRegistration :json-false :linkSupport t)
                        :typeDefinition
                        (:dynamicRegistration :json-false :linkSupport t)
                        :documentSymbol
                        (:dynamicRegistration :json-false :hierarchicalDocumentSymbolSupport t :symbolKind
                                              (:valueSet
                                               [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26]))
                        :documentHighlight
                        (:dynamicRegistration :json-false)
                        :codeAction
                        (:dynamicRegistration :json-false :codeActionLiteralSupport
                                              (:codeActionKind
                                               (:valueSet
                                                ["quickfix" "refactor" "refactor.extract" "refactor.inline" "refactor.rewrite" "source" "source.organizeImports"]))
                                              :isPreferredSupport t)
                        :formatting
                        (:dynamicRegistration :json-false)
                        :rangeFormatting
                        (:dynamicRegistration :json-false)
                        :rename
                        (:dynamicRegistration :json-false)
                        :publishDiagnostics
                        (:relatedInformation :json-false :codeDescriptionSupport :json-false :tagSupport
                                             (:valueSet
                                              [1 2])))
                       :experimental #s(hash-table size 65 test eql rehash-size 1.5 rehash-threshold 0.8125 data
                                                   ()))))
[server-notification] Tue Jan 25 22:22:27 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "Started ElixirLS v0.8.0" :type 4))
[server-notification] Tue Jan 25 22:22:27 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "Elixir version: \"1.10.3 (compiled with Erlang/OTP 22)\"" :type 4))
[server-notification] Tue Jan 25 22:22:27 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "Erlang version: \"22\"" :type 4))
[server-notification] Tue Jan 25 22:22:27 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "ElixirLS compiled with Elixir 1.10.4 and erlang 22" :type 4))
[server-reply] (id:1) Tue Jan 25 22:22:29 2022:
(:id 1 :jsonrpc "2.0" :result
     (:capabilities
      (:codeLensProvider
       (:resolveProvider :json-false)
       :completionProvider
       (:triggerCharacters
        ["." "@" "&" "%" "^" ":" "!"])
       :definitionProvider t :documentFormattingProvider t :documentOnTypeFormattingProvider
       (:firstTriggerCharacter "\n")
       :documentSymbolProvider t :executeCommandProvider
       (:commands
        ["spec:8omSLucKATj1Li6RxRD7H21t6y_QdG0A" "expandMacro:8omSLucKATj1Li6RxRD7H21t6y_QdG0A" "manipulatePipes:8omSLucKATj1Li6RxRD7H21t6y_QdG0A"])
       :foldingRangeProvider t :hoverProvider t :implementationProvider t :macroExpansion t :referencesProvider t :signatureHelpProvider
       (:triggerCharacters
        ["(" ","])
       :textDocumentSync
       (:change 2 :openClose t :save
                (:includeText t))
       :workspace
       (:workspaceFolders
        (:changeNotifications :json-false :supported :json-false))
       :workspaceSymbolProvider t)
      :serverInfo
      (:name "ElixirLS" :version "0.8.0")))
[client-notification] Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :method "initialized" :params #s(hash-table size 65 test eql rehash-size 1.5 rehash-threshold 0.8125 data
                                                            ()))
[client-notification] Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :method "textDocument/didOpen" :params
          (:textDocument
           (:uri "file:///Users/akash/rhea/apps/pegasus/test/workers/horme/mission_timeout_worker_generator_test.exs" :version 0 :languageId "elixir" :text "<REDUCTED>")))
[client-notification] Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :method "workspace/didChangeConfiguration" :params
          (:settings
           (:elixirLS
            ((dialyzerEnabled . :json-false)))))
[server-notification] Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :method "textDocument/publishDiagnostics" :params
          (:diagnostics
           []
           :uri "file:///Users/akash/rhea/apps/pegasus/test/workers/horme/mission_timeout_worker_generator_test.exs"))
[server-notification] Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "MIX_ENV: test" :type 4))
[server-notification] Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "MIX_TARGET: host" :type 4))
[client-request] (id:2) Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :id 2 :method "textDocument/signatureHelp" :params
          (:textDocument
           (:uri "file:///Users/akash/rhea/apps/pegasus/test/workers/horme/mission_timeout_worker_generator_test.exs")
           :position
           (:line 0 :character 39)))
[client-request] (id:3) Tue Jan 25 22:22:29 2022:
(:jsonrpc "2.0" :id 3 :method "textDocument/hover" :params
          (:textDocument
           (:uri "file:///Users/akash/rhea/apps/pegasus/test/workers/horme/mission_timeout_worker_generator_test.exs")
           :position
           (:line 0 :character 39)))
[server-reply] (id:3) Tue Jan 25 22:22:29 2022:
(:id 3 :jsonrpc "2.0" :result
     (:contents
      []
      :range
      (:end
       (:character 43 :line 0)
       :start
       (:character 10 :line 0))))
[server-reply] (id:2) Tue Jan 25 22:22:29 2022:
(:id 2 :jsonrpc "2.0" :result
     (:activeParameter 0 :activeSignature 0 :signatures
                       [(:documentation
                         (:kind "markdown" :value "Defines a module given by name with the given contents.")
                         :label "defmodule(alias, do_block)" :parameters
                         [(:label "alias")
                          (:label "do_block")])]))
[server-notification] Tue Jan 25 22:22:43 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "Compile took 14652 milliseconds" :type 3))
[server-notification] Tue Jan 25 22:22:43 2022:
(:jsonrpc "2.0" :method "textDocument/publishDiagnostics" :params
          (:diagnostics
           [(:message "NewRelic.create_distributed_trace_payload/1 is deprecated. Use distributed_trace_headers/1 instead" :range
                      (:end
                       (:character 0 :line 33)
                       :start
                       (:character 0 :line 33))
                      :severity 2 :source "Elixir")]
           :uri "file:///Users/akash/rhea/apps/core/lib/core/http.ex"))
[server-notification] Tue Jan 25 22:22:43 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "[ElixirLS WorkspaceSymbols] Indexing..." :type 3))
[server-notification] Tue Jan 25 22:22:45 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "[ElixirLS WorkspaceSymbols] Module discovery complete" :type 3))
[server-notification] Tue Jan 25 22:22:46 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "[ElixirLS WorkspaceSymbols] 20 callbacks added to index" :type 3))
[server-notification] Tue Jan 25 22:22:51 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "[ElixirLS WorkspaceSymbols] 263 modules added to index" :type 3))
[server-notification] Tue Jan 25 22:22:54 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "[ElixirLS WorkspaceSymbols] 347 types added to index" :type 3))
[server-notification] Tue Jan 25 22:23:02 2022:
(:jsonrpc "2.0" :method "window/logMessage" :params
          (:message "[ElixirLS WorkspaceSymbols] 4570 functions added to index" :type 3))
[client-notification] Tue Jan 25 22:23:18 2022:
(:jsonrpc "2.0" :method "textDocument/didOpen" :params
          (:textDocument
           (:uri "file:///Users/akash/rhea/apps/horme/lib/horme/api/merchants_controller.ex" :version 0 :languageId "elixir" :text "<REDUCTED>")))
[server-notification] Tue Jan 25 22:23:18 2022:
(:jsonrpc "2.0" :method "textDocument/publishDiagnostics" :params
          (:diagnostics
           []
           :uri "file:///Users/akash/rhea/apps/horme/lib/horme/api/merchants_controller.ex"))

Backtrace (mandatory, unless no error message seen or heard):

Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
  file-truename(nil)
  eglot--path-to-uri(nil)
  eglot--TextDocumentIdentifier()
  eglot--TextDocumentPositionParams()
  eglot-signature-eldoc-function(#f(compiled-function (string &rest plist) #<bytecode 0xef14d65941d95da>))
  #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_19>(eglot-signature-eldoc-function)
  eldoc-documentation-enthusiast()
  eldoc--invoke-strategy(nil)
  eldoc-print-current-symbol-info()
  #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_14>()
  apply(#<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_14> nil)
  timer-event-handler([t 0 0 500000 nil #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_14> nil idle 0 nil])

Minimal configuration (mandatory)

;; Example of a minimal configuration
(setq package-enable-at-startup nil
      package-archives
      '(("melpa" . "http://melpa.milkbox.net/packages/")
        ("gnu" . "http://elpa.gnu.org/packages/")))

(require 'package)
(package-initialize)

(package-install 'eglot)
(package-install 'elixir-mode)
(package-install 'magit)

(add-to-list 'eglot-server-programs `(elixir-mode . ("/Users/akash/elixir-ls/language_server.sh")))

Steps to reproduce

I think the issue is not specific to any language server, so should be possible to reproduce with any git repo. But mentioning the steps for the sake of completeness

• clone and open any elixir git repo
• M-x toggle-debug-on-error
• create an elixir-mode non-visiting-buffer. By opening any file in different revision from magit stash, diff, log etc
• move cursor around to trigger textDocument/signatureHelp

Issue is related to #116. There is a fix for indirect-buffer a1f2033. But in this case this seems to be just a buffer without visiting file.

[joaotavora]

I think this is an Eglot bug, but I don't have a good idea for solving it. it never happens to me when I use VC, for example (I don't use Magit). That's because VC uses an actual file to backup the foo-mode buffers it creates.

LSP requires URIs for things. Should we just make up an URI?

Also I can't find the part in your LSP transcript where the textDocument/signatureHelp is issued. I'm looking for the URI of the file-less buffer thing that it presumably invoked didOpen on.

[hapst3r]

Hej fellows,

I have actually stumbled upon the same issue while trying to enable EGLOT in INFERIOR-PYTHON-MODE (derived from COMINT-MODE, the Python Shell/REPL). I wanted to use the EGLOT-COMPLETION-AT-POINT-FUNCTIONS so that I not only have code completion but also documentation, all provided by the python language server

Here is what I did:

1. install python language server (pylsp)
2. add PYLSP to EGLOT-SERVER-PROGRAMS for INFERIOR-PYTHON-MODE

(add-to-list 'eglot-server-programs
                     '(inferior-python-mode . ("pylsp")))

3. add EGLOT-COMPLETION-AT-POINT to COMPLETION-AT-POINT-FUNCTIONS (using CAPE)

(use-package cape
  :init 
  (defun or/cape-capfs-python-shell-mode ()
    (setq-local completion-at-point-functions
                       '(eglot-completion-at-point
                        python-completion-at-point
                        cape-history
                        comint-completion-at-point
                        t)))
  :hook 
  ((inferior-python-mode . or/cape-capfs-python-shell-mode)))

4. open Python file and associated Python Shell
5. toggle the completion command (COMPLETE-SYMBOL)

Has anything transpired in the meantime to make this possible?

Have a good day :)