umu_run: handle ldconfig failing to find libc.so

- Related to Open-Wine-Components#106

- This is a temporary solution until we figure out how to properly setup an environment for distributions like NixOS so the steam runtime container framework can search for key libraries in shared library paths

umu/umu_run.py

@@ -273,13 +273,19 @@ def enable_steam_game_drive(env: dict[str, str]) -> dict[str, str]:
             break
 
     if os.environ.get("LD_LIBRARY_PATH"):
+        log.debug("LD_LIBRARY_PATH=%s", os.environ["LD_LIBRARY_PATH"])
         paths = {path for path in os.environ["LD_LIBRARY_PATH"].split(":")}
 
     if env["STEAM_COMPAT_INSTALL_PATH"]:
         paths.add(env["STEAM_COMPAT_INSTALL_PATH"])
 
+    # Set the shared library paths of the system after finding libc.so
+    # In some cases, using ldconfig to determine library paths can fail in Non-FHS
+    # compliant filesystems (e.g., NixOS). In those cases, depend on LD_LIBRARY_PATH
+    # See https://github.com/Open-Wine-Components/umu-launcher/issues/106
     for path in steamrt_paths:
-        paths.add(path)
+        if not Path(path).is_symlink() and libc and Path(path, libc).is_file():
+            paths.add(path)
     env["STEAM_RUNTIME_LIBRARY_PATH"] = ":".join(list(paths))
 
     return env