fix dev build namespacing

Author: carderne

packages/cli-v3/src/dev/devSession.ts

@@ -57,13 +57,14 @@ export async function startDevSession({
   dashboardUrl,
   keepTmpFiles,
 }: DevSessionOptions): Promise<DevSessionInstance> {
-  clearTmpDirs(rawConfig.workingDir);
-  const destination = getTmpDir(rawConfig.workingDir, "build", keepTmpFiles);
+  clearTmpDirs(rawConfig.workingDir, branch);
+  const destination = getTmpDir(rawConfig.workingDir, "build", keepTmpFiles, branch);
   // Create shared store directory for deduplicating chunk files across rebuilds
-  const storeDir = getStoreDir(rawConfig.workingDir, keepTmpFiles);
+  const storeDir = getStoreDir(rawConfig.workingDir, keepTmpFiles, branch);
 
   const runtime = await startWorkerRuntime({
     name,
+    branch,
     config: rawConfig,
     args: rawArgs,
     client,
@@ -190,7 +191,7 @@ export async function startDevSession({
           return;
         }
 
-        const workerDir = getTmpDir(rawConfig.workingDir, "build", keepTmpFiles);
+        const workerDir = getTmpDir(rawConfig.workingDir, "build", keepTmpFiles, branch);
         await updateBuild(result, workerDir);
       });
     },

packages/cli-v3/src/dev/devSupervisor.ts

@@ -31,9 +31,12 @@ import { resolveLocalEnvVars } from "../utilities/localEnvVars.js";
 import type { Metafile } from "esbuild";
 import { TaskRunProcessPool } from "./taskRunProcessPool.js";
 import { tryCatch } from "@trigger.dev/core/utils";
+import { devBranchPathSegment } from "../utilities/devBranch.js";
+import { getTmpRoot } from "../utilities/tempDirectories.js";
 
 export type WorkerRuntimeOptions = {
   name: string | undefined;
+  branch?: string;
   config: ResolvedConfig;
   args: DevCommandOptions;
   client: CliApiClient;
@@ -206,8 +209,14 @@ class DevSupervisor implements WorkerRuntime {
       mkdirSync(triggerDir, { recursive: true });
     }
 
-    this.activeRunsPath = join(triggerDir, "active-runs.json");
-    this.watchdogPidPath = join(triggerDir, "watchdog.pid");
+    // Namespace watchdog state per branch so concurrent dev sessions on
+    // different branches don't share a single watchdog instance (the
+    // single-instance guard would otherwise kill the other branch's watchdog).
+    const safeBranch = devBranchPathSegment(this.options.branch);
+    const suffix = safeBranch ? `-${safeBranch}` : "";
+
+    this.activeRunsPath = join(triggerDir, `active-runs${suffix}.json`);
+    this.watchdogPidPath = join(triggerDir, `watchdog${suffix}.pid`);
 
     // Write empty active-runs file
     this.#updateActiveRunsFile();
@@ -232,7 +241,7 @@ class DevSupervisor implements WorkerRuntime {
           WATCHDOG_API_KEY: this.options.client.accessToken ?? "",
           WATCHDOG_ACTIVE_RUNS: this.activeRunsPath,
           WATCHDOG_PID_FILE: this.watchdogPidPath,
-          WATCHDOG_TMP_DIR: join(triggerDir, "tmp"),
+          WATCHDOG_TMP_DIR: getTmpRoot(this.options.config.workingDir, this.options.branch),
         },
       });
 

packages/cli-v3/src/dev/lock.ts

@@ -1,7 +1,7 @@
 import path from "node:path";
 import { readFile } from "../utilities/fileSystem.js";
 import { tryCatch } from "@trigger.dev/core/utils";
-import { isDefaultDevBranch } from "@trigger.dev/core/v3/utils/gitBranch";
+import { devBranchPathSegment } from "../utilities/devBranch.js";
 import { logger } from "../utilities/logger.js";
 import { mkdir, writeFile } from "node:fs/promises";
 import { existsSync, unlinkSync } from "node:fs";
@@ -16,13 +16,8 @@ const LOCK_FILE_NAME = "dev.lock";
  * branches don't kill each other.
  */
 function lockFileName(branch?: string) {
-  if (!branch || isDefaultDevBranch(branch)) {
-    return LOCK_FILE_NAME;
-  }
-
-  // Branch names can contain filesystem-unsafe characters (e.g. "/"), so sanitize.
-  const safeBranch = branch.replace(/[^a-zA-Z0-9-_]/g, "-");
-  return `dev.${safeBranch}.lock`;
+  const safeBranch = devBranchPathSegment(branch);
+  return safeBranch ? `dev.${safeBranch}.lock` : LOCK_FILE_NAME;
 }
 
 export async function createLockFile(cwd: string, branch?: string) {

packages/cli-v3/src/utilities/analyze.ts

@@ -207,8 +207,9 @@ function formatSize(bytes: number): string {
 }
 
 function normalizePath(path: string): string {
-  // Remove .trigger/tmp/build-<hash>/ prefix
-  return path.replace(/(^|\/).trigger\/tmp\/build-[^/]+\//, "");
+  // Remove .trigger/tmp/build-<hash>/ prefix (tmp root may be branch-scoped,
+  // e.g. .trigger/tmp-feature-foo/build-<hash>/)
+  return path.replace(/(^|\/)\.trigger\/tmp(-[^/]+)?\/build-[^/]+\//, "");
 }
 
 interface BundleTreeData {

packages/cli-v3/src/utilities/devBranch.ts

@@ -0,0 +1,19 @@
+import { isDefaultDevBranch } from "@trigger.dev/core/v3/utils/gitBranch";
+
+/**
+ * Derives a filesystem-safe path segment for a dev branch, used to namespace
+ * on-disk artifacts (lock files, the `.trigger/tmp` build tree, watchdog state)
+ * so concurrent `trigger dev` sessions on different branches in the same project
+ * don't clobber each other.
+ *
+ * Returns `undefined` for the default branch (or no branch) so callers keep
+ * their original, branch-less paths for backwards compatibility.
+ */
+export function devBranchPathSegment(branch?: string): string | undefined {
+  if (!branch || isDefaultDevBranch(branch)) {
+    return undefined;
+  }
+
+  // Branch names can contain filesystem-unsafe characters (e.g. "/"), so sanitize.
+  return branch.replace(/[^a-zA-Z0-9-_]/g, "-");
+}

packages/cli-v3/src/utilities/tempDirectories.ts

@@ -1,6 +1,21 @@
 import fs from "node:fs";
 import path from "node:path";
 import { onExit } from "signal-exit";
+import { devBranchPathSegment } from "./devBranch.js";
+
+/**
+ * Resolves the `.trigger/tmp` root for a dev session, scoped to the branch so
+ * concurrent sessions on different branches don't share (and clobber) a build
+ * tree. The default branch keeps the original `.trigger/tmp` path; branches get
+ * a sibling root (e.g. `.trigger/tmp-feature-foo`) so a default-branch
+ * `clearTmpDirs` can't reach into a branch's tree, and vice versa.
+ */
+export function getTmpRoot(projectRoot: string | undefined, branch?: string): string {
+  projectRoot ??= process.cwd();
+  const safeBranch = devBranchPathSegment(branch);
+  const tmpDirName = safeBranch ? `tmp-${safeBranch}` : "tmp";
+  return path.join(projectRoot, ".trigger", tmpDirName);
+}
 
 /**
  * A short-lived directory. Automatically removed when the process exits, but
@@ -21,10 +36,10 @@ export interface EphemeralDirectory {
 export function getTmpDir(
   projectRoot: string | undefined,
   prefix: string,
-  keep: boolean = false
+  keep: boolean = false,
+  branch?: string
 ): EphemeralDirectory {
-  projectRoot ??= process.cwd();
-  const tmpRoot = path.join(projectRoot, ".trigger", "tmp");
+  const tmpRoot = getTmpRoot(projectRoot, branch);
   fs.mkdirSync(tmpRoot, { recursive: true });
 
   const tmpPrefix = path.join(tmpRoot, `${prefix}-`);
@@ -48,9 +63,8 @@ export function getTmpDir(
   };
 }
 
-export function clearTmpDirs(projectRoot: string | undefined) {
-  projectRoot ??= process.cwd();
-  const tmpRoot = path.join(projectRoot, ".trigger", "tmp");
+export function clearTmpDirs(projectRoot: string | undefined, branch?: string) {
+  const tmpRoot = getTmpRoot(projectRoot, branch);
 
   try {
     fs.rmSync(tmpRoot, { recursive: true, force: true });
@@ -65,9 +79,12 @@ export function clearTmpDirs(projectRoot: string | undefined) {
  * identical chunk files between build versions.
  * Automatically cleaned up when the process exits.
  */
-export function getStoreDir(projectRoot: string | undefined, keep: boolean = false): string {
-  projectRoot ??= process.cwd();
-  const storeDir = path.join(projectRoot, ".trigger", "tmp", "store");
+export function getStoreDir(
+  projectRoot: string | undefined,
+  keep: boolean = false,
+  branch?: string
+): string {
+  const storeDir = path.join(getTmpRoot(projectRoot, branch), "store");
   fs.mkdirSync(storeDir, { recursive: true });
 
   // Register exit handler to clean up the store directory