Suggested keybindings snippet errors in init.vim

Adding the suggested "Keybindings and completion" snippet to a legacy init.vim, I get the following syntax error:

E5107: Error loading lua [string ":lua"]:50: 'end' expected (to close 'function' at line 2) near '<eof>'

nvim --version:


$ nvim --version
NVIM v0.5.0-dev+1012-gfe1ebea33
Build type: RelWithDebInfo
LuaJIT 2.1.0-beta3
Compilation: /usr/bin/cc -O2 -g -Og -g -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fno-common -fdiagnostics-color=always -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -DMIN_LOG_LEVEL=3 -I/home/pierre/code/src/github.com/neovim/neovim/build/config -I/home/pierre/code/src/github.com/neovim/neovim/src -I/home/pierre/code/src/github.com/neovim/neovim/.deps/usr/include -I/usr/include -I/home/pierre/code/src/github.com/neovim/neovim/build/src/nvim/auto -I/home/pierre/code/src/github.com/neovim/neovim/build/include
Compiled by pierre@rh2

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

system vimrc file: "$VIM/sysinit.vim" fall-back for $VIM: "/usr/local/share/nvim"

Run :checkhealth for more info

- nvim-lsp version(commit hash): cf627881198acde0b28714211777b4e6f63f47f0
- Is the problem isolated to a particular language server: nope
- Operating system/version: Fedora 33

### How to reproduce the problem from neovim startup

Add the following lines to your init.vim:

```plaintext
lua << EOF
local nvim_lsp = require('lspconfig')
local on_attach = function(client, bufnr)
  local function buf_set_keymap(...) vim.api.nvim_buf_set_keymap(bufnr, ...) end
  local function buf_set_option(...) vim.api.nvim_buf_set_option(bufnr, ...) end

  buf_set_option('omnifunc', 'v:lua.vim.lsp.omnifunc')

  -- Mappings.
  local opts = { noremap=true, silent=true }
  buf_set_keymap('n', 'gD', '<Cmd>lua vim.lsp.buf.declaration()<CR>', opts)
  buf_set_keymap('n', 'gd', '<Cmd>lua vim.lsp.buf.definition()<CR>', opts)
  buf_set_keymap('n', 'K', '<Cmd>lua vim.lsp.buf.hover()<CR>', opts)
  buf_set_keymap('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<CR>', opts)
  buf_set_keymap('n', '<C-k>', '<cmd>lua vim.lsp.buf.signature_help()<CR>', opts)
  buf_set_keymap('n', '<space>wa', '<cmd>lua vim.lsp.buf.add_workspace_folder()<CR>', opts)
  buf_set_keymap('n', '<space>wr', '<cmd>lua vim.lsp.buf.remove_workspace_folder()<CR>', opts)
  buf_set_keymap('n', '<space>wl', '<cmd>lua print(vim.inspect(vim.lsp.buf.list_workspace_folders()))<CR>', opts)
  buf_set_keymap('n', '<space>D', '<cmd>lua vim.lsp.buf.type_definition()<CR>', opts)
  buf_set_keymap('n', '<space>rn', '<cmd>lua vim.lsp.buf.rename()<CR>', opts)
  buf_set_keymap('n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>', opts)
  buf_set_keymap('n', '<space>e', '<cmd>lua vim.lsp.diagnostic.show_line_diagnostics()<CR>', opts)
  buf_set_keymap('n', '[d', '<cmd>lua vim.lsp.diagnostic.goto_prev()<CR>', opts)
  buf_set_keymap('n', ']d', '<cmd>lua vim.lsp.diagnostic.goto_next()<CR>', opts)
  buf_set_keymap('n', '<space>q', '<cmd>lua vim.lsp.diagnostic.set_loclist()<CR>', opts)

  -- Set some keybinds conditional on server capabilities
  if client.resolved_capabilities.document_formatting then
    buf_set_keymap("n", "<space>f", "<cmd>lua vim.lsp.buf.formatting()<CR>", opts)
  elseif client.resolved_capabilities.document_range_formatting then
    buf_set_keymap("n", "<space>f", "<cmd>lua vim.lsp.buf.formatting()<CR>", opts)
  end

  -- Set autocommands conditional on server_capabilities
  if client.resolved_capabilities.document_highlight then
    require('lspconfig').util.nvim_multiline_command [[
      :hi LspReferenceRead cterm=bold ctermbg=red guibg=LightYellow
      :hi LspReferenceText cterm=bold ctermbg=red guibg=LightYellow
      :hi LspReferenceWrite cterm=bold ctermbg=red guibg=LightYellow
      augroup lsp_document_highlight
        autocmd!
        autocmd CursorHold <buffer> lua vim.lsp.buf.document_highlight()
        autocmd CursorMoved <buffer> lua vim.lsp.buf.clear_references()
      augroup END
    ]]
end

for _, lsp in ipairs(servers) do
  nvim_lsp[lsp].setup { on_attach = on_attach }
end
EOF

Actual behaviour

At the next startup, nvim displays the aforementioned error

Expected behaviour

Keybindings are in place with no error

Minimal init.vim or init.lua and code sample

Health check

Checkhealth result

health#lspconfig#check ======================================================================== ## Checking language server protocol configuration - INFO: tsserver: configuration checked. - INFO: yamlls: configuration checked. - INFO: jsonls: configuration checked. - INFO: bashls: configuration checked. - INFO: pyls: configuration checked. - INFO: cssls: configuration checked. - INFO: dockerls: configuration checked. - INFO: gopls: configuration checked.

neovim / nvim-lspconfig