Language server error with "open /dev/null: too many open files *os.PathError"

[GimmyHchs]

I'm using bingo as LSP server in emacs and everything works well.

LSP was broken after I update the source code and rebuild it.

the error appears after commit 95ba275

reproduce steps:

rm $GOPATH/bin/bingo  // remove old version bingo
git checkout 95ba27549b1fe1b38eea0d6b09078fa74823f616
GO111MODULE=on go install

then open emacs.
see errors:

load /path/to/project/root/ successfully! elapsed time: 5 seconds
notify: open  /path/to/project/submodule1/: too many open files
notify: open  /path/to/project/submodule2/: too many open files
....
Error from the Language Server: couldn’t exec ’go [list -f {{context.GOARCH}} {{context.Compiler}} -- unsafe]’: open /dev/null: too many open files *os.PathError (Unknown error)

if I checkout to 5963059
and rebuild again. Everything works well.

[saibing]

@GimmyHchs

please update bingo to latest commit, and tell me the watch dir number as follow:

[GimmyHchs]

load /path/to/project/root/ successfully! elapsed time: 6 seconds, watch dir number: 52, cached: true

[saibing]

@GimmyHchs

Is the error still there?

[GimmyHchs]

YES

[GimmyHchs]

I noticed that the errors only appear when the go-project has many submodules & files

[saibing]

@GimmyHchs

How to reproduce this problem? I can not reproduce it.

[GimmyHchs]

@saibing
I could only reproduce this problem some of my projects.

close this issue until I found the pattern to reproduce.

thx!

[GimmyHchs]

@saibing
I'm using macOS Mojave.

checking the number of opened files by:

$ lsof -n|awk '{print $2}'|sort|uniq -c|sort -nr|more

• projectA -> error
• projectB -> error
• project go-langserver -> normal

reproduce steps:

1. Add a lot of files as Fake-Submodule into project go-langserver
2. Restart bingo-lsp server.

• project go-langserver -> error

========================================
I think the bug appears because opening too many files for cache-features 95ba275#diff-16cb8f09bce858d105c4086d6b676375R239.
and the number of opened files is too large so that exceed the range of my system.

[s-kostyaev]

Also have this issue on latest commit (Also macOS Mojave). I think the root of problem is fsnotify/fsnotify#11

[s-kostyaev]

Possible solution is another fs notify implementation based on https://github.com/fsnotify/fsevents with darwin build tag. I can try to implement it at the weekend.

[saibing]

@s-kostyaev

I feel very happy, if you can solve this problem.

I don't have a Mac to test this problem.

[s-kostyaev]

Ok, I'll try.

[jguenther]

I also am intermittently getting this error in projects with lots of non-go files.

The one I was having trouble with the other day had a python virtualenv in it with a bunch of .py files, and from lsof output for the bingo process it had filehandles open for all of them

(on macos)

[mbana]

[Info  - 10:35:39 AM] notify: open /Users/mbana/work/openbankinguk/bitbucket/conformance-suite/web/node_modules/yorkie: too many open files
...
[Info  - 10:35:39 AM] fsnotify watch dir number: 1135
...

Confirming same issue on Mac.