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Troubleshooting#

Logs#

Server log#

clojure-lsp logs most of what is doing to a file which location could be found:

  • on :log-path if specified in your clojure-lsp config, for example: {:log-path "/tmp/clojure-lsp.out"}
  • Auto generated every server start on /tmp/clojure-lsp.<TIMESTAMP>.out or /var/folders/... for MacOS.
Emacs users You can open server logs in a buffer with M-x lsp-clojure-server-log.

Client<->Server log#

All LSP clients should provide a way to get the jsonrpc logs between client and server, this helps debug the requests and responses content and time.

Check below how to get the logs for most used clients:

Emacs/lsp-mode https://emacs-lsp.github.io/lsp-mode/page/troubleshooting/#log-client-server-json
VSCode/Calva https://calva.io/clojure-lsp/#viewing-the-logs-between-the-client-and-server

An alternative is to pass --trace-level verbose to clojure-lsp during process start and clojure-lsp will log the communication to the server-log.

Server Info#

clojure-lsp has a custom command that prints useful information about the current running clojure-lsp for the current project, it's called clojure/serverInfo/log, some clients already have ways to call that automatically:

  • Emacs lsp-mode: via lsp-clojure-server-info command.
  • VsCode Calva: via Calva Diagnostics: Clojure-lsp Server Info command.
  • Intellij clojure-lsp plugin: via Settings Tools Clojure LSP Copy server info to clipboard option.

Some features are not working#

clojure-lsp uses clj-kondo to analyze the classpath during server initialize for most features work, so make sure you don't see any "Error while looking up classpath..." on clojure-lsp log file.

Please note that clojure-lsp comes bundled with clj-kondo, so you do not have to install it separately.

For more information, check the Classpath scan settings section.

Classpath scan error#

By default clojure-lsp knows how to scan most common clojure projects using the following rules:

  • If the project root has a project.clj file, it'll run lein classpath to get the classpath.
  • If the project root has a deps.edn file, it'll run clojure -Spath to get the classpath.
  • If the project root has a build.boot file, it'll run boot show --fake-classpath to get the classpath.
  • If the project root has a shadow-cljs.edn file, it'll run npx shadow-cljs classpath to get the classpath.

If your project doesn't follow the above rules or you need a custom command to get the classpath you need to configure the project-specs clojure-lsp setting, for more details check the settings section.

Folders not being analyzed/linted#

By default clojure-lsp get source-paths from classpath, for more details check settings section.

  • If the definition lives under a different source dir, you can define source-aliases or source-paths setting as mentioned on settings section.

  • It is also important to get your project-root correct in your client otherwise the source paths will not be found, check the project-root via your LSP client.

  • If you are using deps and using a :local/root dependency to reference another project, i.e.,

{:deps {foo.bar/baz {:local/root "/path/to/foo/project/containing/a/deps.edn"}}}
  • and you are finding that gotoDefinition isn't working when attempting to jump to the namespace in the referenced project, then it could be that your ~/.config/clojure-lsp/config.edn (or legacy ~/.lsp/config.edn) has a source paths entry, i.e., :source-paths ["src" "test"]. This will prevent the lookup from working, as it restricts clojure-lsp to only scan those folders in the current project for sources, and not the other project referenced via the :local/root deps entry. It can be fixed by removing the :source-paths from the config (as clojure-lsp has good defaults anyway). If you do require more specific source paths, then those can be added at the project level.

Wrong diagnostics/lint#

  • clojure-lsp use clj-kondo to lint and cache in a .clj-kondo/.cache dir, try to remove that folder if you think it's not linting correctly
  • clojure-lsp persist the external jars analysis in a .lsp/.cache/ folder, if you have issues with some specific feature, try to remove that dir and restart the server.
  • If you have issues with macros, double check your clj-kondo config.

Missing Add require... on code actions when using CoC and (neo)vim#

If you find, when executing the command (coc-codeaction-line) (or (coc-codeaction-selected) or (coc-codeaction-cursor)), that you aren't getting back all of the code actions you might expect, please ensure that you have, in your coc-settings.json the line disableDiagnostics set to false or better yet, don't have the line there at all :-

---)

Server is not initializing#

Make sure you have the most recent version of clojure-lsp

Check if the executable is working running it from the command line, it should start up and start reading from stdin. Type Content-Length: 51\n\n{"jsonrpc":"2.0","method":"foo","id":1,"params":{}}. After a few moments you should get something like:

$ ./clojure-lsp
Content-Length: 51

{"jsonrpc":"2.0","method":"foo","id":1,"params":{}}

Content-Length: 101

{"jsonrpc":"2.0","id":1,"error":{"code":-32601,"message":"Method not found","data":{"method":"foo"}}}

If that is ok, clojure-lsp logs to /tmp/clojure-lsp.*.out, so watch that file and start your editor.

LSP Clients also generally have a way to trace server interactions. Turn that on and attach both server and client logs to an issue if it's not obvious what's going on.

Vim users For example, if you are using neovim with CoC, first ensure that trace.server is set to verbose in your coc-settings.json file, e.g., 

  "languageserver": {
    "clojure-lsp": {
      "command": "clojure-lsp",
      "filetypes": ["clojure"],
      "disableDiagnostics": false,
      "rootPatterns": ["deps.edn", "project.clj"],
      "additionalSchemes": ["jar", "zipfile"],
      "trace.server": "verbose",
      "initializationOptions": {
        "project-specs": [{
          "project-path": "deps.edn",
          "classpath-cmd": ["clj", "-Spath"]
        }],
        "use-metadata-for-privacy?": true,
      }
    }
  }
Then, once vim has loaded (and clojure-lsp has initialised), you can issue this command: :CocCommand workspace.showOutput This will show the JSON request/response bodies that go between vim and clojure-lsp. Please capture that information if you need help in tracking down the problem you are experiencing (either by reporting github issues, or talking with someone in Slack/Discord or whatever...)

High memory usage#

clojure-lsp uses a native image that helps a lot with memory usage, but there is no hard limit so for huge Clojure projects or projects with lots of dependencies, memory may be a issue because of multiple analysis (keywords, function usages, java class/members etc).

It's possible to retrieve the project analysis of a running clojure-lsp process via the serverInfo command, a :analysis map will contain both internal (your project) and external (project dependencies) count of each analysis used by clojure-lsp, extremally high count of elements (> hundred thousand) tends to increase memory usage + cache size (.lsp/.cache).

As last resource if your project has a enormous number of some specific elements, it's possible to disable some analysis which should help decrease memory usage and even increase performance via the :analysis setting, but keep in mind that some features related to those analysis may not work, for example, {:analysis {:keywords false}} will remove support for find-references of keywords, or {:analysis {:java {:class-definitions false :member-definitions false}}} will completly disable java features like auto completion of java elements.

MacOS#

In some version of MacOS, Apple restrict the binary to run, to fix that run: xattr -d com.apple.quarantine /path/to/clojure-lsp

Last update: April 22, 2025