Add support for virtualenv in installer

Signed-off-by: Jose Enriquez <[email protected]>

install.py

@@ -8,10 +8,17 @@
 """
 import argparse
 import os
+import platform
 import sys
 import shutil
 import subprocess
-import venv
+
+USE_VIRTUALENV = False
+try:
+    import venv
+except ImportError:
+    USE_VIRTUALENV = True
+    import virtualenv
 
 
 source_path = os.path.dirname(os.path.realpath(__file__))
@@ -27,15 +34,36 @@
 from rez.vendor.distlib.scripts import ScriptMaker  # noqa: E402
 
 
-def create_virtual_environment(dest_dir):
-    builder = venv.EnvBuilder(with_pip=True)
-    builder.create(dest_dir)
+def create_virtual_environment(dest_dir: str) -> None:
+    """Create a virtual environment in the given directory.
+
+    Args:
+        dest_dir (str): Full path to the virtual environment directory.
+
+    """
+    if USE_VIRTUALENV:
+        try:
+            subprocess.run(
+                [sys.executable, "-m", "virtualenv", dest_dir],
+                check=True
+            )
+        except subprocess.CalledProcessError as err:
+            print(f"Failed to create virtual environment: {err}")
+            sys.exit(1)
+    else:
+        builder = venv.EnvBuilder(with_pip=True)
+        builder.create(dest_dir)
+
+
+def get_virtualenv_bin_dir(dest_dir: str) -> str:
+    """Get the bin directory of the virtual environment.
 
+    Args:
+        dest_dir (str): The directory of the virtual environment.
 
-def get_virtualenv_bin_dir(dest_dir):
-    builder = venv.EnvBuilder()
-    context = builder.ensure_directories(dest_dir)
-    return context.bin_path
+    """
+    bin_dir = "Scripts" if platform.system() == "Windows" else "bin"
+    return os.path.join(dest_dir, bin_dir)
 
 
 def get_virtualenv_py_executable(dest_dir):