Reset the bootstrapped binaries on install (#1317)

There was not much benefit to avoiding the new download (and it was
broken in some Windows compatibility work) and this ensures there are
_only_ the versions we specified

scripts/bootstrap/install.py

@@ -92,12 +92,14 @@ def sha256_file(path: Path):
 versions_metadata = json.loads(VERSIONS_METADATA_FILE.read_text())
 versions = VERSIONS_FILE.read_text().splitlines()
 
+if INSTALL_DIR.exists():
+    print("Removing existing installations...")
+    shutil.rmtree(INSTALL_DIR)
 
 # Install each version
 for version in versions:
     key = f"{INTERPRETER}-{version}-{PLATFORM_MAP.get(PLATFORM, PLATFORM)}-{ARCH_MAP.get(ARCH, ARCH)}"
     install_dir = INSTALL_DIR / f"{INTERPRETER}@{version}"
-    already_exists = False
     print(f"Installing {key}")
 
     url = versions_metadata[key]["url"]
@@ -107,43 +109,39 @@ def sha256_file(path: Path):
         sys.exit(1)
 
     filename = url.split("/")[-1]
-    if not install_dir.exists():
-        print(f"Downloading {urllib.parse.unquote(filename)}")
-        download_path = THIS_DIR / filename
-        with urllib.request.urlopen(url) as response:
-            with download_path.open("wb") as download_file:
-                shutil.copyfileobj(response, download_file)
-
-        sha = versions_metadata[key]["sha256"]
-        if not sha:
-            print(f"WARNING: no checksum for {key}")
-        else:
-            print("Verifying checksum...", end="")
-            if sha256_file(download_path) != sha:
-                print(" FAILED!")
-                sys.exit(1)
-            print(" OK")
+    print(f"Downloading {urllib.parse.unquote(filename)}")
+    download_path = THIS_DIR / filename
+    with urllib.request.urlopen(url) as response:
+        with download_path.open("wb") as download_file:
+            shutil.copyfileobj(response, download_file)
+
+    sha = versions_metadata[key]["sha256"]
+    if not sha:
+        print(f"WARNING: no checksum for {key}")
+    else:
+        print("Verifying checksum...", end="")
+        if sha256_file(download_path) != sha:
+            print(" FAILED!")
+            sys.exit(1)
+        print(" OK")
 
-        if install_dir.exists():
-            shutil.rmtree(install_dir)
-        print("Extracting to", install_dir)
-        install_dir.parent.mkdir(parents=True, exist_ok=True)
+    if install_dir.exists():
+        shutil.rmtree(install_dir)
+    print("Extracting to", install_dir)
+    install_dir.parent.mkdir(parents=True, exist_ok=True)
 
-        decompress_file(THIS_DIR / filename, install_dir.with_suffix(".tmp"))
+    decompress_file(THIS_DIR / filename, install_dir.with_suffix(".tmp"))
 
-        # Setup the installation
-        (install_dir.with_suffix(".tmp") / "python").rename(install_dir)
-    else:
-        # We need to update executables even if the version is already downloaded and extracted
-        # to ensure that changes to the precedence of versions are respected
-        already_exists = True
-        print("Already available, skipping download")
+    # Setup the installation
+    (install_dir.with_suffix(".tmp") / "python").rename(install_dir)
 
     if PLATFORM == "win32":
         executable = install_dir / "install" / "python.exe"
     else:
         # Use relative paths for links so if the bin is moved they don't break
-        executable = "." / install_dir.relative_to(BIN_DIR) / "install" / "bin" / "python3"
+        executable = (
+            "." / install_dir.relative_to(BIN_DIR) / "install" / "bin" / "python3"
+        )
 
     major = versions_metadata[key]["major"]
     minor = versions_metadata[key]["minor"]
@@ -164,10 +162,7 @@ def sha256_file(path: Path):
         else:
             target.symlink_to(executable)
 
-    if already_exists:
-        print(f"Updated executables for python{version}")
-    else:
-        print(f"Installed executables for python{version}")
+    print(f"Installed executables for python{version}")
 
     # Cleanup
     install_dir.with_suffix(".tmp").rmdir()