add git version for internal testing

setup.py

@@ -19,6 +19,9 @@ import subprocess
 from pathlib import Path
 
 
+if int(os.environ.get('ADD_GIT_VERSION', '0')) == 1:
+    add_git_version = True
+
 def load_module_from_path(module_name, path):
     spec = importlib.util.spec_from_file_location(module_name, path)
     module = importlib.util.module_from_spec(spec)
@@ -309,10 +312,22 @@ def find_version(filepath: str) -> str:
         raise RuntimeError("Unable to find version string.")
 
 
+def get_sha(root: Union[str, Path]) -> str:
+    try:
+        return subprocess.check_output(['git', 'rev-parse', 'HEAD'], cwd=root).decode('ascii').strip()
+    except Exception:
+        return 'Unknown'
+
+
 def get_version_add(sha: Optional[str] = None) -> str:
     vllm_root = os.path.dirname(os.path.abspath(__file__))
     add_version_path = os.path.join(os.path.join(vllm_root, "vllm"), "version.py")
-
+    if add_git_version:
+        if sha != 'Unknown':
+            if sha is None:
+                sha = get_sha(vllm_root)
+            version = 'das.opt1.' + sha[:7]
+    else:
         version = 'das.opt1'
 
     # dtk version