feat: configure version detection for vcs-versioning with tag prefix

- Add _own_version_of_vcs_versioning.py with hatchling code version source
- Configure git_describe_command to match only 'vcs-versioning-*' tags
- Guard setuptools import in _types.py with TYPE_CHECKING
- Set up proper root/fallback_root paths relative to git repo
- Add fallback_version for bootstrap before first tag
- Update _own_version_helper.py docs for future setuptools-scm- prefix

This allows vcs-versioning to:
1. Use its own version detection independent of setuptools-scm
2. Filter tags by 'vcs-versioning-' prefix
3. Bootstrap with fallback version until first proper tag is created
4. Work without setuptools as runtime dependency

Author: RonnyPfannschmidt

_own_version_helper.py

@@ -1,15 +1,20 @@
 """
-this module is a hack only in place to allow for setuptools
-to use the attribute for the versions
+Version helper for setuptools-scm package.
 
-it works only if the backend-path of the build-system section
-from pyproject.toml is respected
+This module allows setuptools-scm to use VCS metadata for its own version.
+It works only if the backend-path of the build-system section from
+pyproject.toml is respected.
+
+Tag prefix configuration:
+- Currently: No prefix (for backward compatibility with existing tags)
+- Future: Will migrate to 'setuptools-scm-' prefix
 """
 
 from __future__ import annotations
 
 import logging
 import os
+import sys
 
 from collections.abc import Callable
 
@@ -57,6 +62,9 @@ def scm_version() -> str:
         else get_local_node_and_date
     )
 
+    # Note: tag_regex is currently NOT set to allow backward compatibility
+    # with existing tags. To migrate to 'setuptools-scm-' prefix, uncomment:
+    # tag_regex=r"^setuptools-scm-(?P<version>[vV]?\d+(?:\.\d+){0,2}[^\+]*)(?:\+.*)?$",
     return get_version(
         relative_to=__file__,
         parse=parse,
@@ -66,6 +74,7 @@ def scm_version() -> str:
 
 
 version: str
+print("__file__", __file__, file=sys.stderr)
 
 
 def __getattr__(name: str) -> str:

nextgen/vcs-versioning/_own_version_of_vcs_versioning.py

@@ -0,0 +1,84 @@
+"""
+Version helper for vcs-versioning package.
+
+This module allows vcs-versioning to use VCS metadata for its own version,
+with the tag prefix 'vcs-versioning-'.
+
+Used by hatchling's code version source.
+"""
+
+from __future__ import annotations
+
+import logging
+import os
+
+from collections.abc import Callable
+
+from vcs_versioning import Configuration
+from vcs_versioning import _types as _t
+from vcs_versioning._backends import _git as git
+from vcs_versioning._backends import _hg as hg
+from vcs_versioning._fallbacks import fallback_version
+from vcs_versioning._fallbacks import parse_pkginfo
+from vcs_versioning._get_version_impl import get_version
+from vcs_versioning._version_schemes import ScmVersion
+from vcs_versioning._version_schemes import get_local_node_and_date
+from vcs_versioning._version_schemes import get_no_local_node
+from vcs_versioning._version_schemes import guess_next_dev_version
+
+log = logging.getLogger("vcs_versioning")
+
+# Try these parsers in order for vcs-versioning's own version
+try_parse: list[Callable[[_t.PathT, Configuration], ScmVersion | None]] = [
+    parse_pkginfo,
+    git.parse,
+    hg.parse,
+    git.parse_archival,
+    hg.parse_archival,
+    fallback_version,  # Last resort: use fallback_version from config
+]
+
+
+def parse(root: str, config: Configuration) -> ScmVersion | None:
+    for maybe_parse in try_parse:
+        try:
+            parsed = maybe_parse(root, config)
+        except OSError as e:
+            log.warning("parse with %s failed with: %s", maybe_parse, e)
+        else:
+            if parsed is not None:
+                return parsed
+    return None
+
+
+def _get_version() -> str:
+    """Get version from VCS with vcs-versioning- tag prefix."""
+    # Use no-local-version if VCS_VERSIONING_NO_LOCAL is set (for CI uploads)
+    local_scheme = (
+        get_no_local_node
+        if os.environ.get("VCS_VERSIONING_NO_LOCAL")
+        else get_local_node_and_date
+    )
+
+    # __file__ is nextgen/vcs-versioning/_own_version_helper.py
+    # pyproject.toml is in nextgen/vcs-versioning/pyproject.toml
+    pyproject_path = os.path.join(os.path.dirname(__file__), "pyproject.toml")
+
+    # root is the git repo root (../..)
+    # fallback_root is the vcs-versioning package dir (.)
+    # relative_to anchors to pyproject.toml
+    # fallback_version is used when no vcs-versioning- tags exist yet
+    return get_version(
+        root="../..",
+        fallback_root=".",
+        relative_to=pyproject_path,
+        parse=parse,
+        version_scheme=guess_next_dev_version,
+        local_scheme=local_scheme,
+        tag_regex=r"^vcs-versioning-(?P<version>[vV]?\d+(?:\.\d+){0,2}[^\+]*)(?:\+.*)?$",
+        git_describe_command="git describe --dirty --tags --long --match 'vcs-versioning-*'",
+        fallback_version="0.1.0+pre.tag",
+    )
+
+
+__version__: str = _get_version()

nextgen/vcs-versioning/pyproject.toml

@@ -2,6 +2,7 @@
 build-backend = "hatchling.build"
 requires = [
   "hatchling",
+  "packaging>=20",
 ]
 
 [project]
@@ -67,7 +68,9 @@ node-and-timestamp = "vcs_versioning._version_schemes:get_local_node_and_timesta
 "release-branch-semver" = "vcs_versioning._version_schemes:release_branch_semver_version"
 
 [tool.hatch.version]
-path = "src/vcs_versioning/__about__.py"
+source = "code"
+path = "_own_version_of_vcs_versioning.py"
+search-paths = ["src"]
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/vcs_versioning"]

nextgen/vcs-versioning/src/vcs_versioning/_requirement_cls.py

@@ -4,17 +4,8 @@
 
 __all__ = ["Requirement", "extract_package_name"]
 
-try:
-    from packaging.requirements import Requirement
-    from packaging.utils import canonicalize_name
-except ImportError:
-    from setuptools.extern.packaging.requirements import (  # type: ignore[import-not-found,no-redef]
-        Requirement as Requirement,
-    )
-    from setuptools.extern.packaging.utils import (  # type: ignore[import-not-found,no-redef]
-        canonicalize_name as canonicalize_name,
-    )
-
+from packaging.requirements import Requirement
+from packaging.utils import canonicalize_name
 
 log = logging.getLogger(__name__)
 

nextgen/vcs-versioning/src/vcs_versioning/_types.py

@@ -9,9 +9,9 @@
 from typing import TypeAlias
 from typing import Union
 
-from setuptools import Distribution
-
 if TYPE_CHECKING:
+    from setuptools import Distribution
+
     from . import _version_schemes as version
     from ._pyproject_reading import PyProjectData
     from ._toml import InvalidTomlError