diff --git a/scripts/scenarios/start-app.ts b/scripts/scenarios/start-app.ts
index 5dee3f26c1..893601f000 100644
--- a/scripts/scenarios/start-app.ts
+++ b/scripts/scenarios/start-app.ts
@@ -126,6 +126,11 @@ const startApp = Effect.fn("startApp")(function* (input: {
   const checkout = yield* HostProcess.WorkingDirectory;
   const hostEnvironment = yield* HostProcess.Environment;
   yield* prepareHome(input.home);
+  const inheritedGit = path.join(input.home, "other-checkout", ".git");
+  yield* fs.makeDirectory(path.join(inheritedGit, "objects"), { recursive: true });
+  yield* fs.makeDirectory(path.join(inheritedGit, "refs"), { recursive: true });
+  yield* fs.writeFileString(path.join(inheritedGit, "HEAD"), "ref: refs/heads/main\n");
+  yield* fs.writeFileString(path.join(inheritedGit, "config"), '[core]\n  repositoryformatversion = 0\n  bare = false\n[remote "upstream"]\n  gh-resolved = base\n');
   const env = {
     ...hostEnvironment,
     PATH: `${path.join(input.home, "bin")}:${hostEnvironment.PATH ?? ""}`,
@@ -155,6 +160,9 @@ const startApp = Effect.fn("startApp")(function* (input: {
       args: devRunner("dev:server", ports),
       env: {
         ...webEnv,
+        GIT_DIR: inheritedGit,
+        GIT_CONFIG_GLOBAL: "/dev/null",
+        T3CODE_DEV_SEED: "0",
         T3CODE_DEV_ALLOWED_ORIGINS: origin,
         // Makes the startup pairing link reusable, so every test can sign in with it.
         T3CODE_DEV_AUTH_TOKEN: `${token}${token}`.replaceAll("-", ""),