diff --git a/supacode/Domain/WorktreeProjectKind.swift b/supacode/Domain/WorktreeProjectKind.swift
index 43419672..9f139348 100644
--- a/supacode/Domain/WorktreeProjectKind.swift
+++ b/supacode/Domain/WorktreeProjectKind.swift
@@ -96,12 +96,9 @@ enum WorktreeProjectKind: CaseIterable {
   /// when a repo carries a pathological manifest.
   nonisolated private static func markerFileContents(named name: String, in directory: URL) -> String? {
     let url = directory.appending(path: name, directoryHint: .notDirectory)
-    guard let handle = try? FileHandle(forReadingFrom: url),
-      let data = try? handle.read(upToCount: 128 * 1024)
-    else {
-      return nil
-    }
-    try? handle.close()
+    guard let handle = try? FileHandle(forReadingFrom: url) else { return nil }
+    defer { try? handle.close() }
+    guard let data = try? handle.read(upToCount: 128 * 1024) else { return nil }
     return String(data: data, encoding: .utf8)
   }
 
diff --git a/supacodeTests/TemporaryProjectDirectory.swift b/supacodeTests/TemporaryProjectDirectory.swift
index d538a3b1..399d0b47 100644
--- a/supacodeTests/TemporaryProjectDirectory.swift
+++ b/supacodeTests/TemporaryProjectDirectory.swift
@@ -31,23 +31,28 @@ private func makeTemporaryProjectDirectory(
   let directory = fileManager.temporaryDirectory
     .appending(path: "project-fixture-\(UUID().uuidString)")
   try fileManager.createDirectory(at: directory, withIntermediateDirectories: true)
-  for entry in entries {
-    if entry.hasSuffix("/") {
+  do {
+    for entry in entries {
+      if entry.hasSuffix("/") {
+        try fileManager.createDirectory(
+          at: directory.appending(path: String(entry.dropLast())),
+          withIntermediateDirectories: true
+        )
+      } else {
+        try Data().write(to: directory.appending(path: entry))
+      }
+    }
+    for (path, data) in contents {
+      let fileURL = directory.appending(path: path)
       try fileManager.createDirectory(
-        at: directory.appending(path: String(entry.dropLast())),
+        at: fileURL.deletingLastPathComponent(),
         withIntermediateDirectories: true
       )
-    } else {
-      try Data().write(to: directory.appending(path: entry))
+      try data.write(to: fileURL)
     }
-  }
-  for (path, data) in contents {
-    let fileURL = directory.appending(path: path)
-    try fileManager.createDirectory(
-      at: fileURL.deletingLastPathComponent(),
-      withIntermediateDirectories: true
-    )
-    try data.write(to: fileURL)
+  } catch {
+    try? fileManager.removeItem(at: directory)
+    throw error
   }
   return directory
 }