Make formatting manual for now

Objections were raised about automatic installation of hooks.

doc/manual/src/contributing/hacking.md

@@ -192,15 +192,30 @@ Configure your editor to use the `clangd` from the shell, either by running it i
 > Some other editors (e.g. Emacs, Vim) need a plugin to support LSP servers in general (e.g. [lsp-mode](https://github.com/emacs-lsp/lsp-mode) for Emacs and [vim-lsp](https://github.com/prabirshrestha/vim-lsp) for vim).
 > Editor-specific setup is typically opinionated, so we will not cover it here in more detail.
 
-## Pre-commit and formatting
+## Formatting and pre-commit
+
+You may run the formatters as a one-off using:
+
+```console
+make format
+```
+
+<!-- TBD, opt-in, blocked on https://github.com/cachix/pre-commit-hooks.nix/pull/261
+
+If you'd like to run the formatters before every commit, install the hooks:
+
+```
+nix-pre-commit-hooks-install
+```
 
 `nix develop` installs Nix-[integrated](https://github.com/cachix/pre-commit-hooks.nix) [pre-commit](https://pre-commit.com) hooks.
 
-The formatters will run when you commit.
-Pay attention to the console output. If it fails, run `git add --patch` to
+When the hook fails, because files were updated, run `git add --patch` to
 approve the suggestions _and commit again_.
 
-The hook configuration is only regenerated when you start a new dev shell.
+-->
+
+The hook configuration is only regenerated when you start a new development shell.
 
 ## Running tests
 

maintainers/flake-module.nix

@@ -9,6 +9,9 @@
 
     # https://flake.parts/options/pre-commit-hooks-nix.html#options
     pre-commit.settings = {
+
+      default_stages = [ "manual" ];
+
       hooks = {
         clang-format.enable = true;
         nixpkgs-fmt.enable = true;

maintainers/local.mk

@@ -7,4 +7,4 @@ format:
 	  echo "make format: pre-commit not found. Please use \`nix develop\`."; \
 	  exit 1; \
 	fi; \
-	pre-commit run --all-files
+	pre-commit run --all-files --hook-stage manual