diff --git a/.clangd b/.clangd
index e07ab19..aec1172 100644
--- a/.clangd
+++ b/.clangd
@@ -1,13 +1,13 @@
 # Editor accommodations for the second frontend. No compilation database is
 # named here: this driver is made to be vendored, and this file travels with
-# it — a consumer's own database then covers these headers, at the consumer's
+# it - a consumer's own database then covers these headers, at the consumer's
 # chip. The checkout that is opened as a folder names its build tree in
 # .vscode/settings.json instead.
 CompileFlags:
   Add:
     # clang has no 24-bit integer and GCC's are keywords, not macros, so the
     # editor needs a stand-in for avr::uint24_t. The next width up is the only
-    # one available — clang rejects _BitInt(24) on this target.
+    # one available - clang rejects _BitInt(24) on this target.
     - -D__uint24=unsigned long
     - -D__int24=long
     # clangd forwards the driver's system includes but not its own header
@@ -16,7 +16,7 @@ CompileFlags:
     - -D__STDC_LIMIT_MACROS
     - -D__STDC_CONSTANT_MACROS
     # isr::emit spells a vector number into [[gnu::signal(N)]], which clang
-    # rejects rather than ignores — enough of them in one TU to reach the
+    # rejects rather than ignores - enough of them in one TU to reach the
     # default limit of 19 inside the headers and truncate the parse.
     - -ferror-limit=0
   Remove:
diff --git a/.gitattributes b/.gitattributes
index 6755504..3b9741d 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,12 +1,8 @@
-# Line endings are the repository's, not the editing machine's: this checkout
-# is reached from two hosts, and a file rewritten by a Windows tool comes back
-# with every line changed unless something says otherwise. Naming the source
-# extensions left Markdown, Python, shell and CMake to whatever the writing
-# tool defaulted to, which is CRLF on one of the two.
+# Line endings are the repository's, not the editing tool's (libavr guidance
+# rule 50): a file rewritten by a Windows tool must not come back with every
+# line changed.
 * text=auto eol=lf
 
 # Atmel Studio writes these and expects them back.
-*.vcxproj*  eol=crlf
 *.cppproj   eol=crlf
-*.sln       eol=crlf
 *.atsln     eol=crlf
diff --git a/.vscode/settings.json b/.vscode/settings.json
index d598a4e..3eb5f75 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -7,25 +7,28 @@
 	// --query-driver lets clangd ask the cross compiler for its own system
 	// includes and target. The database is named here rather than in .clangd
 	// because that file travels with the driver into a consumer's submodule,
-	// where a build tree of this repo's own need not exist.
+	// where a build tree of this repo's own need not exist. It sits one level
+	// above the trees, and CMake Tools copies the selected preset's into it on
+	// every configure: the database carries `-mmcu`, so a fixed tree would
+	// check the driver against one chip.
 	"clangd.arguments": [
-		"--compile-commands-dir=${workspaceFolder}/build/atmega328p-generated",
+		"--compile-commands-dir=${workspaceFolder}/build",
 		"--query-driver=**avr-g++*",
 		"--header-insertion=never"
 	],
+	"cmake.copyCompileCommands": "${workspaceFolder}/build/compile_commands.json",
 
 	// The presets are the build interface, and the toolchain file inside the
-	// libavr submodule is the one place the compiler is chosen. **No prefix is
-	// named here**: a committed file may not name a path that is true of one
-	// machine (libavr guidance rule 50), so the gitignored local/machine.cmake
-	// at this repository's root is where a checkout says where its toolchain
-	// is - one file, and it answers for both hosts.
+	// libavr submodule is the one place the compiler is chosen. No prefix is
+	// named here: the gitignored local/machine.cmake at this repository's root
+	// is where a checkout says where its toolchain is (libavr guidance rule 50).
 	"cmake.useCMakePresets": "always",
 	"cmake.configureOnOpen": true,
 	"cmake.options.statusBarVisibility": "compact",
 
 	"files.watcherExclude": {
 		"**/build/**": true,
+		"**/local/**": true,
 		"**/libavr/**": true
 	},
 
diff --git a/tools/check.sh b/tools/check.sh
index 40de33e..314b042 100755
--- a/tools/check.sh
+++ b/tools/check.sh
@@ -1,11 +1,11 @@
 #!/usr/bin/env bash
 # The task gate: every configure preset built, and only then every one tested.
 #
-# The loop itself is libavr's (tools/check-presets.sh) because the order in it
-# is subtle and was got wrong by hand more than once - the mode-identity checks
-# read the sibling mode's tree, so a build-then-test-per-preset run compares a
-# fresh image against a stale sibling. Anything this repository needs beyond
-# the presets is written after the call, where every tree is built and tested.
+# The loop itself is libavr's (tools/check-presets.sh): the mode-identity
+# checks read the sibling mode's tree, so a build-then-test-per-preset run
+# would compare a fresh image against a stale sibling. Anything this repository
+# needs beyond the presets is written after the call, where every tree is built
+# and tested.
 set -euo pipefail
 cd "$(dirname "${BASH_SOURCE[0]}")/.."
 "${LIBAVR_ROOT:-libavr}/tools/check-presets.sh" "$@"