fix(py37): add importlib.metadata compatibility shim for Python 3.7

Python 3.7 doesn't have built-in importlib.metadata (added in 3.8).
Added try/except fallback to importlib_metadata backport package in all
import locations.

Files fixed:
- src/omnipkg/commands/run.py
- src/omnipkg/core.py
- src/omnipkg/integration/cli_executor.py
- src/omnipkg/integration/environment.py
- src/omnipkg/isolation/worker_daemon.py (dynamic code execution)
- src/omnipkg/loader.py (dynamic code execution)
- src/omnipkg/package_meta_builder.py

This resolves 'ModuleNotFoundError: No module named importlib.metadata'
on Python 3.7 installations.

Author: 1minds3t

src/omnipkg/commands/run.py

@@ -945,7 +945,10 @@ def is_package_corrupted(pkg_name, missing_module_name):
     Checks if a package is 'Ghosted' (metadata exists so pip thinks it's installed,
     but the actual module cannot be imported).
     """
-    import importlib.metadata
+    try:
+
    import importlib.metadata as importlib_metadata
+
except ImportError:
+
    import importlib_metadata
     import importlib.util
 
     # 1. Is it installed according to metadata?

src/omnipkg/core.py

@@ -12,7 +12,10 @@
     from omnipkg.common_utils import safe_print, print_header
 
 import hashlib
-import importlib.metadata
+try:
+
    import importlib.metadata as importlib_metadata
+
except ImportError:
+
    import importlib_metadata
 import io
 import json
 import locale as sys_locale
@@ -13461,7 +13464,10 @@ def _get_file_list_for_packages_live(self, package_names: List[str]) -> Dict[str
 import sys, json, traceback
 
 try:
-    import importlib.metadata as metadata
+    try:
+        import importlib.metadata as metadata
+    except ImportError:
+        import importlib_metadata as metadata
 except ImportError:
     import importlib_metadata as metadata
 

src/omnipkg/integration/cli_executor.py

@@ -5,7 +5,10 @@
 This makes omnipkg actually usable for real development work
 """
 
-import importlib.metadata
+try:
+
    import importlib.metadata as importlib_metadata
+
except ImportError:
+
    import importlib_metadata
 import os
 import shutil
 import subprocess

src/omnipkg/integration/environment.py

@@ -7,7 +7,10 @@
 have to prefix commands with '8pkg run'
 """
 
-import importlib.metadata
+try:
+
    import importlib.metadata as importlib_metadata
+
except ImportError:
+
    import importlib_metadata
 import os
 import shutil
 import stat

src/omnipkg/isolation/worker_daemon.py

@@ -3350,7 +3350,7 @@ def execute(self, code: str):
             }
 
     def get_version(self, package_name):
-        code = f"import importlib.metadata; result = {{'version': importlib.metadata.version('{package_name}'), 'path': __import__('{package_name}').__file__}}"
+        code = f"try: import importlib.metadata as meta\nexcept ImportError: import importlib_metadata as meta\nresult = {{'version': meta.version('{package_name}'), 'path': __import__('{package_name}').__file__}}"
         res = self.execute(code)
         if res.get("success"):
             return {"success": True, "version": "unknown", "path": "daemon"}

src/omnipkg/loader.py

@@ -4004,7 +4004,7 @@ def execute(self, code: str) -> dict:
     def get_version(self, package_name):
         # Execute code to get version and path
         # The worker extracts the local variable named 'result' and merges it into the response
-        code = f"import importlib.metadata; result = {{'version': importlib.metadata.version('{package_name}'), 'path': __import__('{package_name}').__file__}}"
+        code = f"try: import importlib.metadata as meta\nexcept ImportError: import importlib_metadata as meta\nresult = {{'version': meta.version('{package_name}'), 'path': __import__('{package_name}').__file__}}"
         res = self.execute(code)
 
         if res.get("success"):

src/omnipkg/package_meta_builder.py

@@ -14,7 +14,10 @@
 """
 import concurrent.futures
 import hashlib
-import importlib.metadata
+try:
+
    import importlib.metadata as importlib_metadata
+
except ImportError:
+
    import importlib_metadata
 import json
 import os
 import re