diff --git a/dot_local/share/dotup/packages.tsv b/dot_local/share/dotup/packages.tsv
index a5b87a3..2c3bae4 100644
--- a/dot_local/share/dotup/packages.tsv
+++ b/dot_local/share/dotup/packages.tsv
@@ -30,6 +30,7 @@
 @needs	agents/pi-plugins	agents/pi
 @needs	agents/specify-cli	core/uv
 @needs	core/mermaid-cli	core/node
+@needs	core/tree-sitter	core/node
 # The three rows with no apt package at all. They resolved to brew and
 # nothing installed brew, so `^a` ticked them and they failed on every
 # fresh Linux box. On Linux brew lives entirely under
@@ -47,6 +48,7 @@
 @spec	agents/pi-plugins	@juicesharp/rpiv-ask-user-question @juicesharp/rpiv-btw @juicesharp/rpiv-todo @samfp/pi-memory @tmustier/pi-ralph-wiggum pi-markdown-preview pi-powerline-footer pi-simplify pi-subagents pi-web-access
 @spec	agents/specify-cli	specify-cli
 @spec	core/mermaid-cli	@mermaid-js/mermaid-cli
+@spec	core/tree-sitter	tree-sitter-cli
 @spec	core/bitwarden-cli	bw
 @spec	apps/obsidian	md.obsidian.Obsidian
 @spec	apps/chrome	https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
@@ -69,6 +71,7 @@ core	brew	safe	-script	-builtin	linuxbrew — the only source for lazygit, omp a
 core	node	safe	-tarball	node	apt ships 18.19 and the npm rows below need 20+ — tarball to /opt/node
 core	imagemagick	safe	imagemagick	imagemagick	required by the nvim markdown render path
 core	mermaid-cli	safe	-npm	-npm	mmdc — nvim renders mermaid fences with it
+core	tree-sitter	safe	-npm	-npm	tree-sitter CLI — nvim-treesitter (main) refuses to start without it
 core	btop	safe	btop	btop
 core	htop	safe	htop	htop
 core	ncdu	safe	ncdu	ncdu
diff --git a/private_dot_config/nvim/lua/config/lazy.lua b/private_dot_config/nvim/lua/config/lazy.lua
index d73bfa1..8a94d11 100644
--- a/private_dot_config/nvim/lua/config/lazy.lua
+++ b/private_dot_config/nvim/lua/config/lazy.lua
@@ -31,6 +31,10 @@ require("lazy").setup({
     -- version = "*", -- try installing the latest stable version for plugins that support semver
   },
   install = { colorscheme = { "tokyonight", "habamax" } },
+  -- No luarocks. The only consumer is oxocarbon's incidental rockspec, the
+  -- colorscheme works without it, and hererocks compiling lua 5.1 on a fresh
+  -- box fails on missing readline headers (live, 2026-08-23 phase 5 VM).
+  rocks = { enabled = false, hererocks = false },
   checker = {
     enabled = true, -- check for plugin updates periodically
     notify = false, -- notify on update
diff --git a/private_dot_config/nvim/lua/plugins/ai_assist.lua b/private_dot_config/nvim/lua/plugins/ai_assist.lua
index d61092c..2b066d4 100644
--- a/private_dot_config/nvim/lua/plugins/ai_assist.lua
+++ b/private_dot_config/nvim/lua/plugins/ai_assist.lua
@@ -1,6 +1,9 @@
 return {
   dir = vim.fn.expand("~/code/nvim-ai-assist"),
   name = "nvim_ai_assist",
+  -- A local checkout that only some machines have. Without the cond, every
+  -- fresh box reports "Local plugin does not exist" on first sync.
+  cond = vim.fn.isdirectory(vim.fn.expand("~/code/nvim-ai-assist")) == 1,
   lazy = false,
   cmd = { "AI", "AIHealth", "AIRefreshContext" },
   keys = {