A missing language server gives a poor error message

[llimllib]

• nvim --version:

NVIM v0.5.0-dev+78f0f00cd

Build type: Release LuaJIT 2.1.0-beta3 Compilation: /usr/bin/clang -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 -DNDEBUG -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fno-common -fdiagnostics-color=auto -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -DMIN_LOG_LEVEL=3 -I/tmp/neovim-20210125-25323-1inurn2/build/config -I/tmp/neovim-20210125-25323-1inurn2/src -I/usr/local/include -I/tmp/neovim-20210125-25323-1inurn2/deps-build/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include -I/usr/local/opt/gettext/include -I/tmp/neovim-20210125-25323-1inurn2/build/src/nvim/auto -I/tmp/neovim-20210125-25323-1inurn2/build/include Compiled by llimllib@threebody

Features: +acl +iconv +tui
See ":help feature-compile"

system vimrc file: "$VIM/sysinit.vim"
fall-back for $VIM: "/usr/local/Cellar/neovim/HEAD-78f0f00/share/nvim"

Run :checkhealth for more info

• nvim-lsp version(commit hash): 0c8f28f
• What language server (If the problem is related to a specific language server): I believe this is not related to a particular language server
• Is the problem isolated to a particular language server: I don't believe so
• Operating system/version: Mac OS 11.2

How to reproduce the problem from neovim startup

1. Do not have diagnostic-languageserver installed
2. Foolishly add lua config for it that you copied from somewhere else

-- to install run: -- yarn global add diagnostic-languageserver lsp.diagnosticls.setup({ on_attach = on_attach, filetypes={ "markdown", "javascript", "typescript", "javascriptreact", "typescriptreact" }, init_options = { linters = { eslint = { sourceName = "eslint", command = "eslint_d", rootPatterns = { ".git" }, args = { "--stdin", "--stdin-filename", "%filepath", "--format", "json" }, debounce = 100, parseJson = { errorsRoot = "[0].messages", line = "line", column = "column", endLine = "endLine", endColumn = "endColumn", message = "${message} [${ruleId}]", security = "severity" }, securities = { [2] = "error", [1] = "warning", }, }, markdownlint = { sourceName = "markdownlint", command = "markdownlint", args = { "--stdin" }, isStderr = true, debounce = 100, offsetLine = 0, offsetColumn = 0, formatLines = 1, formatPattern = { "^.*?:\\s+(\\d+):\\s+(.*)(\\r|\\n)*$", { line = 1, column = -1, message = 2 } } } }, filetypes = { markdown = "markdownlint", javascript = "eslint", typescript = "eslint", javascriptreact = "eslint", typescriptreact = "eslint", } } })

3. Run neovim on one of the configured filetypes
4. get a confusing error:

Error detected while processing FileType Autocommands for "markdown":
E5108: Error executing lua ...share/nvim/plugged/nvim-lspconfig/lua/lspconfig/util.lua:248: attempt to index field 'log' (a nil value)
Press ENTER or type command to continue

5. install dynamic-languageserver and note that you no longer get no errors

Actual behaviour

Get an error attempt to index field 'log'

Expected behaviour

Get an error that indicates there's a problem with the diagnostic-languageserver not being present

(I tried to repro this error with your minimal_init.lua, but got stuck at:

E5113: Error while calling lua chunk: minimal_init.lua:10: Vim(packadd):E919: Directory not found in 'packpath': "pack/*/opt/packer.nvim"

)

[lithammer]

Too old Neovim version I suspect. You need neovim/neovim#13843 which was merged some 9 days ago.

[mjlbach]

Yep, update your nightly and the problem should be gone.

[llimllib]

Confirmed, apologies for the specious report.

[mjlbach]

No worries, I usually only merge changes that require an updated nightly after ~1 week once the feature hits core. This won't be an issue once 0.5 is cut (no idea when that will be though).