From c4ac851187308128bb2ea7960c4f301f06b15d71 Mon Sep 17 00:00:00 2001
From: Mikael Hugo <mikkihugo@users.noreply.github.com>
Date: Sat, 2 May 2026 15:24:14 +0200
Subject: [PATCH] fix(sf): isolate sift warmup cache per project

---
 .../extensions/sf/code-intelligence.ts        | 35 ++++++++++++++++--
 .../sf/tests/code-intelligence.test.ts        | 36 +++++++++++++++++--
 2 files changed, 65 insertions(+), 6 deletions(-)

diff --git a/src/resources/extensions/sf/code-intelligence.ts b/src/resources/extensions/sf/code-intelligence.ts
index d37c18ecb..aab552625 100644
--- a/src/resources/extensions/sf/code-intelligence.ts
+++ b/src/resources/extensions/sf/code-intelligence.ts
@@ -144,6 +144,29 @@ const DEFAULT_SIFT_WARMUP_RETRIEVER_TIMEOUT_MS = 30_000;
 const DEFAULT_SIFT_WARMUP_HARD_TIMEOUT_SEC = 30;
 const SIFT_WARMUP_KILL_GRACE_SEC = 10;
 
+function resolveSiftWarmupRuntimeDirs(projectRoot: string): {
+	cacheHome: string;
+	tmpDir: string;
+} {
+	const runtimeRoot = join(projectRoot, ".sf", "runtime", "sift");
+	return {
+		cacheHome: join(runtimeRoot, "xdg-cache"),
+		tmpDir: join(runtimeRoot, "tmp"),
+	};
+}
+
+function buildSiftWarmupEnv(
+	projectRoot: string,
+	env: NodeJS.ProcessEnv,
+): NodeJS.ProcessEnv {
+	const dirs = resolveSiftWarmupRuntimeDirs(projectRoot);
+	return {
+		...env,
+		XDG_CACHE_HOME: dirs.cacheHome,
+		TMPDIR: dirs.tmpDir,
+	};
+}
+
 function readJsonConfig(configPath: string): McpConfigFile {
 	if (!existsSync(configPath)) return {};
 	const raw = readFileSync(configPath, "utf-8");
@@ -488,7 +511,11 @@ export function ensureSiftIndexWarmup(
 			: "sift page-index-hybrid warmup started (no timeout(1)/gtimeout on PATH; running unbounded)";
 
 	try {
+		const runtimeDirs = resolveSiftWarmupRuntimeDirs(projectRoot);
 		mkdirSync(join(projectRoot, ".sf", "runtime"), { recursive: true });
+		mkdirSync(runtimeDirs.cacheHome, { recursive: true });
+		mkdirSync(runtimeDirs.tmpDir, { recursive: true });
+		const childEnv = buildSiftWarmupEnv(projectRoot, env);
 		writeFileSync(
 			markerPath,
 			`${JSON.stringify(
@@ -500,6 +527,8 @@ export function ensureSiftIndexWarmup(
 					args,
 					siftBinary: detection.binaryPath,
 					hardTimeoutSec: wrapper?.timeoutSec ?? null,
+					cacheHome: runtimeDirs.cacheHome,
+					tmpDir: runtimeDirs.tmpDir,
 				},
 				null,
 				2,
@@ -509,7 +538,7 @@ export function ensureSiftIndexWarmup(
 
 		const child = (options.spawnFn ?? spawn)(command, args, {
 			cwd: projectRoot,
-			env,
+			env: childEnv,
 			stdio: "ignore",
 			detached: true,
 		});
@@ -791,7 +820,7 @@ function buildSiftContextLines(
 				'`--strategy path-hybrid` for path-heavy queries, and `sift search <path> --agent "<task>"` for bounded planner-driven exploration.',
 		);
 		lines.push(
-			"- Sift uses a sector-aware cache in the platform cache directory, typically `~/.cache/sift`; " +
+			"- SF runs Sift warmup with project-scoped cache/temp directories under `.sf/runtime/sift/`; " +
 				"if the CLI is missing or fails, continue with `.sf/CODEBASE.md`, native `grep`/`find`/`ls`, `lsp`, and scout.",
 		);
 	} else {
@@ -960,7 +989,7 @@ export function formatSiftStatus(
 		'When configured, agents should use `sift search --json <path> "<query>"`; `page-index-hybrid` is the strongest direct-search preset and `path-hybrid` is best for path-heavy queries.',
 	);
 	lines.push(
-		"Sift reuses a sector-aware cache in the platform cache directory, typically ~/.cache/sift.",
+		"SF runs Sift warmup with project-scoped cache/temp directories under .sf/runtime/sift/.",
 	);
 	return lines.join("\n");
 }
diff --git a/src/resources/extensions/sf/tests/code-intelligence.test.ts b/src/resources/extensions/sf/tests/code-intelligence.test.ts
index abc31c052..6e64a6cdb 100644
--- a/src/resources/extensions/sf/tests/code-intelligence.test.ts
+++ b/src/resources/extensions/sf/tests/code-intelligence.test.ts
@@ -499,9 +499,17 @@ test("ensureSiftIndexWarmup defaults optional warmup hard cap to 30 seconds", ()
 		const fakeTimeout = join(projectRoot, "bin", "timeout");
 		writeFileSync(fakeTimeout, "", "utf-8");
 
-		const calls: Array<{ command: string; args: string[] }> = [];
-		const fakeSpawn = ((command: string, args: string[]) => {
-			calls.push({ command, args });
+		const calls: Array<{
+			command: string;
+			args: string[];
+			options?: { env?: NodeJS.ProcessEnv };
+		}> = [];
+		const fakeSpawn = ((command: string, args: string[], options?: unknown) => {
+			calls.push({
+				command,
+				args,
+				options: options as { env?: NodeJS.ProcessEnv },
+			});
 			return { unref() {} };
 		}) as unknown as typeof import("node:child_process").spawn;
 
@@ -520,6 +528,28 @@ test("ensureSiftIndexWarmup defaults optional warmup hard cap to 30 seconds", ()
 			fakeSift,
 		]);
 		assert.match(result.reason, /hard cap 30s/);
+		assert.equal(
+			calls[0].options?.env?.XDG_CACHE_HOME,
+			join(projectRoot, ".sf", "runtime", "sift", "xdg-cache"),
+		);
+		assert.equal(
+			calls[0].options?.env?.TMPDIR,
+			join(projectRoot, ".sf", "runtime", "sift", "tmp"),
+		);
+		const marker = JSON.parse(
+			readFileSync(
+				join(projectRoot, ".sf", "runtime", "sift-index-warmup.json"),
+				"utf-8",
+			),
+		);
+		assert.equal(
+			marker.cacheHome,
+			join(projectRoot, ".sf", "runtime", "sift", "xdg-cache"),
+		);
+		assert.equal(
+			marker.tmpDir,
+			join(projectRoot, ".sf", "runtime", "sift", "tmp"),
+		);
 	} finally {
 		cleanup(projectRoot);
 	}