enhance build process to handle locked artifacts and ensure directory creation

build.py

@@ -4,6 +4,8 @@ from pathlib import Path
 import PyInstaller.__main__
 import typer
 from rich import print
+import time
+from datetime import datetime
 
 
 app = typer.Typer()
@@ -70,17 +72,62 @@ def build(build: bool = True, copy: bool = True, test: bool = False, dest: str |
             except Exception as e:
                 print(f"Warning: couldn't locate pythonnet runtime: {e}")
 
+            # Ensure dist/work/spec directories exist
+            dist_dir = project_root / "dist" / "test"
+            work_dir = project_root / "build" / "test"
+            spec_dir = project_root / "build" / "specs"
+            dist_dir.mkdir(parents=True, exist_ok=True)
+            work_dir.mkdir(parents=True, exist_ok=True)
+            spec_dir.mkdir(parents=True, exist_ok=True)
+
+            # Decide build name and try to remove any locked previous artifact.
+            base_name = "Uploader_test"
+            output_exe = dist_dir / f"{base_name}.exe"
+
+            def try_remove_with_retries(path: Path, retries: int = 5, delay: float = 0.5) -> bool:
+                """Try to remove a file with retries and backoff. Returns True if removed or not present."""
+                if not path.exists():
+                    return True
+                for attempt in range(retries):
+                    try:
+                        path.unlink()
+                        print(f"Removed existing file: {path}")
+                        return True
+                    except PermissionError:
+                        # Try to move/rename it out of the way
+                        try:
+                            backup = path.with_suffix(f".old.{int(time.time())}")
+                            path.rename(backup)
+                            print(f"Renamed locked file to: {backup}")
+                            return True
+                        except Exception:
+                            pass
+                        print(f"File locked, retrying in {delay} seconds ({attempt+1}/{retries})")
+                        time.sleep(delay)
+                        delay *= 1.5
+                    except Exception as e:
+                        print(f"Failed to remove existing file {path}: {e}")
+                        return False
+                return False
+
+            name_used = base_name
+            if not try_remove_with_retries(output_exe):
+                # If the previous artifact is locked, fall back to a unique name to avoid build failure
+                ts = datetime.now().strftime("%Y%m%dT%H%M%S")
+                name_used = f"{base_name}_{ts}"
+                print(f"Previous artifact appears locked; building as {name_used} to avoid PermissionError")
+
             PyInstaller.__main__.run([
                 str(project_root / "nice.py"),
                 "--onefile",
                 "--name",
-                "Uploader_test",
+                name_used,
                 "--distpath",
-                str(project_root / "dist" / "test"),
+                str(dist_dir),
                 "--workpath",
-                str(project_root / "build" / "test"),
+                str(work_dir),
                 "--specpath",
-                str(project_root / "build" / "specs"),
+                str(spec_dir),
             ] + add_data_args + add_binary_args + [
                 # add some common hidden imports that PyInstaller sometimes misses
                 "--hidden-import",