[BUG] Vim 9.1 intermittently freezes while saving, "Failed to intercept" error

[stevejmp]

Describe the bug
Vim 9.1 intermittently freezes while saving/writing Clojure buffers in a small project (using Leiningen), sometimes displaying the following error on the cmdline at the bottom:

Failed to intercept for :elin.constant.interceptor/autocmd: error occured on entering elin.interceptor.autocmd/ns-load because of 'No implementation of method: :as-file of protocol: #'clojure.java.io/Coercions found for class: clojure.lang.PersistentVector'

To Reproduce
The behavior is intermittent, but it seems to be related to using fzf.vim to open a file.

1. Change directory to the affected project
2. Launch vim, opening any Clojure file: `vim src/<PATH_TO_CLJ_FILE>
3. Connect to a REPL
4. Use the :Files command from fzf.vim to open another Clojure file
5. Make a small change to the buffer
6. Write/save the change to file: :w
7. Repeat steps 5 and 6 until the behavior is triggered
8. When the behavior is triggered, vim freezes before actually writing the file, and the error message is sometimes displayed.

Expected behavior
Vim does not freeze, but instead writes the file and continues to function properly.

Environment (please complete the following information):

• Editor: Vim
• Editor version: 2:9.1.0016-1ubuntu7.8
• Babashka version: babashka v1.12.197

Configuration file (if you have):
User configuration ($XDG_CONFIG_HOME/elin/config.edn or$HOME/.config/elin/config.edn)
(none)

Project local configuration (YOUR_PROJECT/.elin/config.edn)
(none)

Additional context
Seems related to #30.

[liquidz]

@stevejmp Thansk for your reporting!

Hmm, I could not reproduce the problem...

elin.interceptor.autocmd/ns-load only runs on BufRead or BufEnter, so I don't think it's related to saving with :w.

elin/src/elin/interceptor/autocmd.clj

Line 50 in f6dcd1b

(ix/when #(and (bufread-or-bufenter? %)

Interceptor execution on BufWritePre uses elin#intercept_request to wait for a response from the elin server, as was discussed in #30.
This is intentional, to support features like automatic formatting on save.

elin/plugin/elin.vim

Line 53 in f6dcd1b

au BufWritePre *.clj,*.cljs,*.cljc,*.cljd call elin#intercept_request('BufWritePre')

And since it is not something that triggers frequently like CursorMovedI, I didn't expect it to be an issue — but it's possible that, due to some problem, it's getting stuck waiting at this point.

[liquidz]

@stevejmp As a temporary workaround, I’ve added a g:elin_notify_on_bufwrite_pre option in the WIP-44 branch.
It defaults to false, so could you try setting it to true and check how it behaves?

[stevejmp]

To confirm, I first reproduced the issue several times on WIP-44 without any changes.

After setting the variable as follows, I could no longer reproduce the issue 👍

let g:elin_notify_on_bufwrite_pre = v:true

Note again that the issue occurs after both opening files via fzf.vim AND writing buffers multiple times.

This can even occur on a newly opened file and writing the buffer only one time, if I had already written multiple fzf-opened files beforehand.

As to whether it gets stuck, or receives the wrong data, I'm not sure. At this point, all I have is the error message (see first post in the issue) that only sometimes displays.

I'm more than happy continuing to help debug further. Please let me know what you need.

Thanks!