Fix nvim transparency to preserve foreground colors

[jorgemanrubia]

Summary

• The old transparency.lua used vim.api.nvim_set_hl(0, name, { bg = "none" }) which replaces the entire highlight definition, wiping out foreground and other attributes — not just the background
• This breaks snacks.nvim's GitHub integration (<leader>gp for PRs, <leader>gi for issues) which reads the foreground color from Normal/NormalFloat at module load time, gets nil, and crashes with "Finder not found: gh_pr"
• The fix uses nvim_get_hl to fetch existing attributes first, removes only bg, then sets the highlight back — preserving all other attributes

Companion PR for fresh installs (source file): omacom-io/omarchy-pkgs#51

Root cause

snacks/util/init.lua:187: attempt to index local 'fg' (a nil value)

The snacks.gh module computes diff highlight colors at require-time by calling Snacks.util.color("Normal") to get the foreground. Since the transparency script cleared it, fg is nil and Snacks.util.blend(nil, bg, alpha) crashes. The pcall in the picker's finder resolution catches this, and the picker reports "Finder not found".

Test plan

• Open nvim in a git repo and press <leader>gp — should open the GitHub PR picker without errors
• Verify transparent backgrounds still work correctly
• Verify foreground colors are preserved (text should look the same as before)

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Updates the Neovim transparency migration so transparent highlights no longer wipe existing foreground/style attributes, preventing plugins (e.g., snacks.nvim GitHub pickers) from reading nil highlight colors at load time.

Changes:

• Add a new migration that rewrites ~/.config/nvim/plugin/after/transparency.lua to preserve existing highlight attributes while clearing only background.
• Apply transparency across a defined list of common UI/plugin highlight groups.

Comments suppressed due to low confidence (2)

migrations/1772389838.sh:68

• This migration overwrites the entire ~/.config/nvim/plugin/after/transparency.lua whenever it exists. That’s a behavior change from the earlier transparency migration (migrations/1771667323.sh) which patched the file in-place, and it can clobber user customizations or other injected highlight tweaks. Consider making this migration update only the specific nvim_set_hl(... { bg = "none" }) pattern (or only overwrite if the file matches an expected template), and/or writing a backup before replacing the file.

if [[ -f "$TRANSPARENCY_FILE" ]]; then
  cat > "$TRANSPARENCY_FILE" << 'EOF'
-- Make highlight groups transparent while preserving their other attributes
local function make_transparent(name)
	local ok, hl = pcall(vim.api.nvim_get_hl, 0, { name = name, link = false })
	if ok then
		hl.bg = nil
		vim.api.nvim_set_hl(0, name, hl)
	else
		vim.api.nvim_set_hl(0, name, { bg = "none" })
	end
end

local groups = {
	-- transparent background
	"Normal",
	"NormalFloat",
	"FloatBorder",
	"Pmenu",
	"Terminal",
	"EndOfBuffer",
	"FoldColumn",
	"Folded",
	"SignColumn",
	"LineNr",
	"CursorLineNr",
	"NormalNC",
	"WhichKeyFloat",
	"TelescopeBorder",
	"TelescopeNormal",
	"TelescopePromptBorder",
	"TelescopePromptTitle",
	-- neotree
	"NeoTreeNormal",
	"NeoTreeNormalNC",
	"NeoTreeVertSplit",
	"NeoTreeWinSeparator",
	"NeoTreeEndOfBuffer",
	-- nvim-tree
	"NvimTreeNormal",
	"NvimTreeVertSplit",
	"NvimTreeEndOfBuffer",
	-- notify
	"NotifyINFOBody",
	"NotifyERRORBody",
	"NotifyWARNBody",
	"NotifyTRACEBody",
	"NotifyDEBUGBody",
	"NotifyINFOTitle",
	"NotifyERRORTitle",
	"NotifyWARNTitle",
	"NotifyTRACETitle",
	"NotifyDEBUGTitle",
	"NotifyINFOBorder",
	"NotifyERRORBorder",
	"NotifyWARNBorder",
	"NotifyTRACEBorder",
	"NotifyDEBUGBorder",
}

for _, name in ipairs(groups) do
	make_transparent(name)
end
EOF

migrations/1772389838.sh:13

• The Lua code in the heredoc uses tab indentation, but this repo’s .editorconfig specifies indent_style = space / indent_size = 2. To keep formatting consistent (and avoid whitespace churn in future edits), consider reindenting the embedded Lua with 2 spaces instead of tabs.

local function make_transparent(name)
	local ok, hl = pcall(vim.api.nvim_get_hl, 0, { name = name, link = false })
	if ok then
		hl.bg = nil
		vim.api.nvim_set_hl(0, name, hl)
	else

---

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[dhh]

Can you show where this is broken?

Also, need to change the base of the config in addition to just a migration (since those are only applied to existing systems, not new installs).

[jorgemanrubia]

With the original transparency.lua I get this error when pressing <leader>gp:

Can you reproduce yourself? I haven't messed with my neovim config that I know of, but I have been running Omarchy for a while, so there is a chance it is local to my box.

I had already created a PR to change the base config here omacom-io/omarchy-pkgs#51

[dhh]

Ohh! I had never used that feature. It's broken here too 😄