Revert "tools: add ability to grab git tag (pytorch#77279)"

This reverts commit ba55296.

Reverted pytorch#77279 on behalf of https://github.com/seemethere

tools/generate_torch_version.py

@@ -6,9 +6,6 @@
 from typing import Optional, Union
 
 
-UNKNOWN = "Unknown"
-
-
 def get_sha(pytorch_root: Union[str, Path]) -> str:
     try:
         return (
@@ -17,20 +14,7 @@ def get_sha(pytorch_root: Union[str, Path]) -> str:
             .strip()
         )
     except Exception:
-        return UNKNOWN
-
-
-def get_tag(pytorch_root: Union[str, Path]) -> str:
-    try:
-        return (
-            subprocess.check_output(
-                ["git", "describe", "--tags", "--exact"], cwd=pytorch_root
-            )
-            .decode("ascii")
-            .strip()
-        )
-    except Exception:
-        return UNKNOWN
+        return "Unknown"
 
 
 def get_torch_version(sha: Optional[str] = None) -> str:
@@ -43,7 +27,7 @@ def get_torch_version(sha: Optional[str] = None) -> str:
         version = os.getenv("PYTORCH_BUILD_VERSION", "")
         if build_number > 1:
             version += ".post" + str(build_number)
-    elif sha != UNKNOWN:
+    elif sha != "Unknown":
         if sha is None:
             sha = get_sha(pytorch_root)
         version += "+git" + sha[:7]
@@ -70,13 +54,8 @@ def get_torch_version(sha: Optional[str] = None) -> str:
 
     pytorch_root = Path(__file__).parent.parent
     version_path = pytorch_root / "torch" / "version.py"
-    # Attempt to get tag first, fall back to sha if a tag was not found
-    tagged_version = get_tag(pytorch_root)
     sha = get_sha(pytorch_root)
-    if tagged_version == UNKNOWN:
-        version = get_torch_version(sha)
-    else:
-        version = tagged_version
+    version = get_torch_version(sha)
 
     with open(version_path, "w") as f:
         f.write("__version__ = '{}'\n".format(version))