adjust the way we build miri-script in RA, to fix proc-macros

etc/rust_analyzer_vscode.json

@@ -5,21 +5,19 @@
         "cargo-miri/Cargo.toml",
         "miri-script/Cargo.toml",
     ],
-    "rust-analyzer.check.invocationLocation": "root",
     "rust-analyzer.check.invocationStrategy": "once",
     "rust-analyzer.check.overrideCommand": [
-        "env",
-        "MIRI_AUTO_OPS=no",
         "./miri",
         "clippy", // make this `check` when working with a locally built rustc
         "--message-format=json",
     ],
+    "rust-analyzer.cargo.extraEnv": {
+        "MIRI_AUTO_OPS": "no",
+        "MIRI_IN_RA": "1",
+    },
     // Contrary to what the name suggests, this also affects proc macros.
-    "rust-analyzer.cargo.buildScripts.invocationLocation": "root",
     "rust-analyzer.cargo.buildScripts.invocationStrategy": "once",
     "rust-analyzer.cargo.buildScripts.overrideCommand": [
-        "env",
-        "MIRI_AUTO_OPS=no",
         "./miri",
         "check",
         "--message-format=json",

miri

@@ -3,12 +3,16 @@ set -e
 # We want to call the binary directly, so we need to know where it ends up.
 ROOT_DIR="$(dirname "$0")"
 MIRI_SCRIPT_TARGET_DIR="$ROOT_DIR"/miri-script/target
-# If stdout is not a terminal and we are not on CI, assume that we are being invoked by RA, and use JSON output.
-if ! [ -t 1 ] && [ -z "$CI" ]; then
+TOOLCHAIN="+nightly"
+# If we are being invoked for RA, use JSON output and the default toolchain (to make proc-macros
+# work in RA). This needs a different target dir to avoid mixing up the builds.
+if [ -n "$MIRI_IN_RA" ]; then
   MESSAGE_FORMAT="--message-format=json"
+  TOOLCHAIN=""
+  MIRI_SCRIPT_TARGET_DIR="$ROOT_DIR"/miri-script/target/ra
 fi
 # We need a nightly toolchain, for `-Zroot-dir`.
-cargo +nightly build $CARGO_EXTRA_FLAGS --manifest-path "$ROOT_DIR"/miri-script/Cargo.toml \
+cargo $TOOLCHAIN build $CARGO_EXTRA_FLAGS --manifest-path "$ROOT_DIR"/miri-script/Cargo.toml \
   -Zroot-dir="$ROOT_DIR" \
   -q --target-dir "$MIRI_SCRIPT_TARGET_DIR" $MESSAGE_FORMAT || \
   ( echo "Failed to build miri-script. Is the 'nightly' toolchain installed?"; exit 1 )