What may be causing custom server config to NOT be utilized? (Omnisharp on Linux)

[Blake-LeBlanc]

(This question may relate more to mason-lspconfig.nvim, the issue form on that repo directed me here)

I've noticed that regardless of what I include in the custom omnisharp.lua file, the configuration outlined in :LspInfo seems to indicate the default cmd that is cobbled together in nvim-lspconfig.

I suspect there's something I'm not doing right in setting up mason.nvim and mason-lspconfig.nvim since the cmd output updates when I use williamboman/nvim-lsp-installer.

That said, I haven't been able to get omnisharp to work in either case. This is on Linux (Ubuntu 20.04.4), trying to get it up and running for Unity C# Mono scripts.

Any ideas where I might be going wrong?

As you can see in the code below in the configs.lua file, I've tried making using the omnisharp-roslyn that comes with :MasonInstall as well as a direct reference to the mono complete package I installed separately per the instructions at https://www.mono-project.com/download/stable/ .

I wouldn't be surprised if I need to somehow integrate Mason's omnisharp-mono server rather than omnisharp, but whenever I try that route, it rightly complains that nvim-lspconfig does not have a corresponding "match" to refer to.

Thanks in advance for any help!

/home/linux/dotfiles/neovim/.config/nvim/lua/user/lsp/configs.lua

local status_ok, lsp_installer = pcall(require, "mason")
-- local status_ok, mason = pcall(require, "mason")
if not status_ok then
	return
end

local lspconfig = require("lspconfig")
local mason_lspconfig = require("mason-lspconfig")

-- https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md
-- https://github.com/williamboman/mason.nvim/blob/main/lua/mason-registry/index.lua

local servers = {
  "bashls",
  "omnisharp",
    -- FIXME: How to set this up for the mono version in mason?
    -- "omnisharp-mono",
  "sumneko_lua",
  "tsserver",

}

lsp_installer.setup({
  ensure_installed = servers,

})

for _, server in pairs(servers) do
  local opts = {
    on_attach = require("user.lsp.handlers").on_attach,
    capabilities = require("user.lsp.handlers").capabilities,
  }
  
  local has_custom_opts, server_custom_opts = pcall(require, "user.lsp.settings." .. server)
  if has_custom_opts then
    opts = vim.tbl_deep_extend("force", opts, server_custom_opts)
  end

  -- NOTE: This is what was used with `nvim-lsp-installer`
  -- lspconfig[server].setup(opts)

  -- NOTE: This is what I'm attempting to use for `mason` and `mason-lspconfig`
  mason_lspconfig.setup({
    lspconfig[server].setup(opts)
  })

end

plugins

use('neovim/nvim-lspconfig')
use('williamboman/mason.nvim')
use('williamboman/mason-lspconfig.nvim')

Treemap of directory structure, just to help give some context

And just ignore those extra omnisharp_MASON.lua, etc files, those are just where I'm backing up my various trial-and-error attempts

lsp/settings/omnisharp.lua

return {
  config = {
    -- cmd = { "mono", "/home/linux/.local/share/nvim/mason/packages/omnisharp/OmniSharp.Roslyn.dll" },
    cmd = { "mono", "/bin/mono" },
    use_modern_net = false,

    --- From defaults
    enable_editorconfig_support = true,
    enable_roslyn_analyzers = false,
    organize_imports_on_format = false,
    enable_import_completion = false,
    sdk_include_prereleases = true,
    analyze_open_documents_only = false,
    filetypes = { 'cs', 'vb' },

  },
}

:LspInfo

 1 client(s) attached to this buffer: 
 
 Client: omnisharp (id: 5, pid: 12456, bufnr: [119])
 	filetypes:       cs, vb
 	autostart:       true
 	root directory:  /home/linux/<redacted>
 	cmd:             omnisharp -z -s /home/linux/<redacted> --hostPID 1627 DotNet:enablePackageRestore=false --encoding utf-8 --languageserver FormattingOptions:EnableEditorConfigSupport=true Sdk:IncludePrereleases=true

That cmd output seems to come from how the cmd is built in the following...

/nvim-lspconfig/lua/lspconfig/server_configurations/omnisharp.lua

...

on_new_config = function(new_config, new_root_dir)
    table.insert(new_config.cmd, '-z') -- https://github.com/OmniSharp/omnisharp-vscode/pull/4300
    vim.list_extend(new_config.cmd, { '-s', new_root_dir })
    vim.list_extend(new_config.cmd, { '--hostPID', tostring(vim.fn.getpid()) })
    table.insert(new_config.cmd, 'DotNet:enablePackageRestore=false')
    vim.list_extend(new_config.cmd, { '--encoding', 'utf-8' })
    table.insert(new_config.cmd, '--languageserver')

    if new_config.enable_editorconfig_support then
      table.insert(new_config.cmd, 'FormattingOptions:EnableEditorConfigSupport=true')
    end

    if new_config.organize_imports_on_format then
      table.insert(new_config.cmd, 'FormattingOptions:OrganizeImports=true')
    end

    if new_config.enable_ms_build_load_projects_on_demand then
      table.insert(new_config.cmd, 'MsBuild:LoadProjectsOnDemand=true')
    end

    if new_config.enable_roslyn_analyzers then
      table.insert(new_config.cmd, 'RoslynExtensionsOptions:EnableAnalyzersSupport=true')
    end

    if new_config.enable_import_completion then
      table.insert(new_config.cmd, 'RoslynExtensionsOptions:EnableImportCompletion=true')
    end

    if new_config.sdk_include_prereleases then
      table.insert(new_config.cmd, 'Sdk:IncludePrereleases=true')
    end

    if new_config.analyze_open_documents_only then
      table.insert(new_config.cmd, 'RoslynExtensionsOptions:AnalyzeOpenDocumentsOnly=true')
    end
  end,
...

[williamboman]

Hello! So the duality of Omnisharp's different runtimes (Mono vs .NET) is a bit messy. By default, the .NET variant will be used if you request omnisharp to be installed.

If you want to use the Mono variant, I'd recommend doing the following:

• Separate omnisharp from your other lspconfig servers (i.e., remove from the ensure_installed table, and set it up separately outside of the for loop)
• Install the omnisharp-mono package (manually or automated via mason-tool-installer.nvim)
• When setting up omnisharp via lspconfig, set the use_modern_net = false flag:

local servers = {
  "bashls",
  "sumneko_lua",
  "tsserver",

}

mason_lspconfig.setup({
  ensure_installed = servers,
})

for _, server in pairs(servers) do
  local opts = {
    on_attach = require("user.lsp.handlers").on_attach,
    capabilities = require("user.lsp.handlers").capabilities,
  }
  
  local has_custom_opts, server_custom_opts = pcall(require, "user.lsp.settings." .. server)
  if has_custom_opts then
    opts = vim.tbl_deep_extend("force", opts, server_custom_opts)
  end

  lspconfig[server].setup(opts)
end

lspconfig.omnisharp.setup {
  use_modern_net = false
}

I also noticed you're calling:

  mason_lspconfig.setup({
    lspconfig[server].setup(opts)
  })

It's a bit of a weird expression that I'm not gonna describe in detail - but, remove it :D

[Blake-LeBlanc]

First, thanks for the detailed report! It helps me tremendously

Glad to hear it, you're welcome!

I can't really see any reasons for changing the cmd for Omnisharp. The docs in lspconfig suggest that it is necessary, but mason takes care of that for you.

Oh very cool! That's good to know, awesome change!

Looking at the :LspInfo output at the end, it seems fine to me. Is the server not working with that setup?

No, it doesn't seem to ever attach. The full-blown :LspInfo output confirms 0 client(s) to this buffer: (full output at the bottom of this post)

Before I dive into that though, let me take a quick moment to clarify something on my end.

Looking back over your earlier post, I saw you had...

mason_lspconfig.setup({
  ensure_installed = servers,
})

Whenever I have it set up that way, none of the installed servers are recognized. When I open a related file, neovim immediately messages;

Spawning language server with cmd: `<server>` failed. The language server is either not installed, missing from PATH, or not executable.

However, when I use the NON-masonized version:

lspconfig.setup({
  ensure_installed = servers,
})

The named servers are discovered and work okay (lua, bash, typescript, etc).

But this leaves me with an "empty" mason_lspconfig.setup() call just sitting there in the config doing nothing.

I only kick-off with that just in case maybe there's something there on my end that's preventing the omnisharp/omnisharp-mono servers from working their magic.

---

Okay, so to dive back into omnisharp...

Immediately upon loading a *.cs file, the following message displays across the bottom

Client 1 quit with exit code 2 and signal 0

So I pull up the logs and see...

:LspLog

[START][2022-08-10 22:01:26] LSP logging initiated
[ERROR][2022-08-10 22:01:26] .../vim/lsp/rpc.lua:439	"rpc"	"omnisharp-mono"	"stderr"	"Cannot open assembly '/home/linux/.local/share/nvim/mason/bin/omnisharp/OmniSharp.exe': Not a directory.\n"

Which actually seems consintent with mason's current (new?) directory structure. Because while it's looking for an omnisharp directory within /bin, it now looks to be laid out differently

$ ls

(jobs:0) linux:/home/linux/.local/share/nvim/mason/bin 
$ ls
total 12
drwxr-xr-x 2 linux linux 4096 Aug 10 21:54 .
drwxr-xr-x 5 linux linux 4096 Jul 28 16:36 ..
lrwxrwxrwx 1 linux linux   71 Aug 10 21:53 bash-language-server -> ../packages/bash-language-server/node_modules/.bin/bash-language-server
lrwxrwxrwx 1 linux linux   51 Aug 10 21:53 lua-language-server -> ../packages/lua-language-server/lua-language-server
lrwxrwxrwx 1 linux linux   31 Aug 10 21:54 omnisharp -> ../packages/omnisharp/omnisharp
lrwxrwxrwx 1 linux linux   30 Aug 10 21:54 omnisharp-mono -> ../packages/omnisharp-mono/run

And as we'd expect, :LspInfo shows it unattached

:LspInfo

 Language client log: /home/linux/.local/state/nvim/lsp.log
 Detected filetype:   cs
 
 0 client(s) attached to this buffer: 
 
 2 active client(s) not attached to this buffer: 
 
 Client: sumneko_lua (id: 2, pid: 68593, bufnr: [17, 16, 8])
 	filetypes:       lua
 	autostart:       true
 	root directory:  /home/linux/dotfiles
 	cmd:             lua-language-server
 
 Client: null-ls (id: 3, pid: 5001, bufnr: [17, 16, 8])
 	filetypes:       markdown, yaml, html, less, typescriptreact, javascriptreact, scss, javascript, css, typescript, graphql, vue, jsonc, json, handlebars, python, lua
 	autostart:       false
 	root directory:  /home/linux/dotfiles
 	cmd:             nvim
 
 Other clients that match the filetype: cs
 
 Config: omnisharp
 	filetypes:         cs, vb
 	root directory:    /home/linux/<redacted>
 	cmd:               omnisharp-mono -z -s /home/linux/<redacted> --hostPID 68548 DotNet:enablePackageRestore=false --encoding utf-8 --languageserver FormattingOptions:EnableEditorConfigSupport=true RoslynExtensionsOptions:EnableAnalyzersSupport=true Sdk:IncludePrereleases=true -z -s /home/linux/<redacted> --hostPID 68548 DotNet:enablePackageRestore=false --encoding utf-8 --languageserver FormattingOptions:EnableEditorConfigSupport=true RoslynExtensionsOptions:EnableAnalyzersSupport=true Sdk:IncludePrereleases=true
 	cmd is executable: true
 	autostart:         true
 	custom handlers:   
 
 Configured servers list: sumneko_lua, omnisharp, bashls

Which, just for comparison, is different from what happens with nvim-lsp-installer. There, it will attach, the keymaps defined in handlers.lua work, it just won't do anything useful. Everything returns with "No information available".

:LspInfo with nvim-lsp-installer

 Language client log: /home/linux/.local/state/nvim/lsp.log
 Detected filetype:   cs
 
 1 client(s) attached to this buffer: 
 
 Client: omnisharp (id: 1, pid: 78287, bufnr: [4])
 	filetypes:       cs, vb
 	autostart:       true
 	root directory:  /home/linux/<redacted>
 	cmd:             mono /home/linux/.local/share/nvim/lsp_servers/omnisharp/omnisharp-mono/OmniSharp.exe --languageserver --hostPID 78259
 
 Configured servers list: omnisharp, bashls, sumneko_lua

---

---

EDIT: And just to give some additional context, I have BOTH omnisharp and omnisharp-mono installed through Mason. If I ever try to run with JUST omnisharp-mono, I'm quickly met with the following message upon opening a related file

Error detected while processing BufReadPost Autocommands for "*":                                                                                                                        
Error executing lua callback: /usr/local/share/nvim/runtime/filetype.lua:20: Vim(lua):[lspconfig] cmd not defined for "omnisharp". Manually set cmd in the setup {} call according to server_confi
gurations.md, see :help lspconfig-index.
stack traceback:
        [C]: in function 'nvim_buf_set_option'
        /usr/local/share/nvim/runtime/filetype.lua:20: in function </usr/local/share/nvim/runtime/filetype.lua:11>

Once I :MasonInstall omnisharp and restart, that error goes away and we're back at where we started this post.

Thanks again!

[williamboman]

I saw you were using some old variable names like lsp_installer for require("mason"), so I'm tbh not sure what variable is what in your example 😬. ensure_installed should work fine.

I ran into more issues with the omnisharp-mono, see:

• fix(omnisharp_mono): add dedicated server entry for omnisharp_mono mason-lspconfig.nvim#32
• fix(omnisharp-mono): don't link directly to the run script #290

Could you try pulling the latest plugin versions and instead of setting up omnsiharp, set up omnisharp_mono instead? This should also now be supported by ensure_installed, so you can revert back to your earlier variant where you loop through servers:

local servers = {
  "bashls",
  "sumneko_lua",
  "tsserver",
  "omnisharp_mono",
}

mason_lspconfig.setup({
  ensure_installed = servers,
})

for _, server in pairs(servers) do
  local opts = {
    on_attach = require("user.lsp.handlers").on_attach,
    capabilities = require("user.lsp.handlers").capabilities,
  }
  
  local has_custom_opts, server_custom_opts = pcall(require, "user.lsp.settings." .. server)
  if has_custom_opts then
    opts = vim.tbl_deep_extend("force", opts, server_custom_opts)
  end

  lspconfig[server].setup(opts)
end

[williamboman]

See https://github.com/williamboman/mason-lspconfig.nvim/blob/main/lua/mason-lspconfig/server_configurations/omnisharp/README.md for further explanatio!

[Blake-LeBlanc]

Could you try pulling the latest plugin versions and instead of setting up omnsiharp, set up omnisharp_mono instead? This should also now be supported by ensure_installed, so you can revert back to your earlier variant where you loop through servers

Okay, I'll try tomorrow and report back!

[Blake-LeBlanc]

@williamboman Good news, thanks to your recent updates, the omnisharp_mono LSP is attaching! :)

 Language client log: /home/linux/.local/state/nvim/lsp.log
 Detected filetype:   cs
 
 1 client(s) attached to this buffer: 
 
 Client: omnisharp_mono (id: 1, pid: 6582, bufnr: [19])
 	filetypes:       cs, vb
 	autostart:       true
 	root directory:  <redacted>
 	cmd:             omnisharp-mono -z -s <redacted> --hostPID 6566 DotNet:enablePackageRestore=false --encoding utf-8 --languageserver FormattingOptions:EnableEditorConfigSupport=true Sdk:IncludePrereleases=true
 
 Configured servers list: omnisharp_mono, bashls, sumneko_lua

:LspLog does report issues, but from what I read and after trying to resolve it over the weekend, it seems like that's something on my end not related to Mason.

[ERROR][2022-08-15 14:41:35] .../vim/lsp/rpc.lua:439	"rpc"	"omnisharp-mono"	"stderr"	""
[WARN][2022-08-15 14:41:37] ...lsp/handlers.lua:485	"OmniSharp.CompositionHostBuilder: It looks like you have Mono installed which contains a MSBuild lower than 17.0.0 which is the minimum supported by the configured .NET Core Sdk.\n Try updating Mono to the latest stable or preview version to enable better .NET Core Sdk support. | "

Thank you again for all your help William, I appreciate everything you did to help get it this far!

high fives