minimize bootstrap - fixes #722 and #723

enable self-bootstrap without typing_extensions and importlib_metadata

they are still install requirements however

Author: RonnyPfannschmidt

pyproject.toml

@@ -1,9 +1,6 @@
 [build-system]
 requires = [
     "setuptools>=45",
-    "tomli>=1.0",
     "packaging>=20.0",
-    "typing_extensions",
-    "importlib_metadata",
 ]
 build-backend = "setuptools.build_meta"

src/setuptools_scm/__init__.py

@@ -10,7 +10,6 @@
 from typing import Callable
 from typing import TYPE_CHECKING
 
-from . import _types as _t
 from ._entrypoints import _call_entrypoint_fn
 from ._entrypoints import _version_from_entrypoints
 from ._overrides import _read_pretended_version_for
@@ -33,6 +32,7 @@
 if TYPE_CHECKING:
     from typing import NoReturn
 
+    from . import _types as _t
 
 TEMPLATES = {
     ".py": """\

src/setuptools_scm/_entrypoints.py

@@ -6,18 +6,20 @@
 from typing import overload
 from typing import TYPE_CHECKING
 
-from typing_extensions import Protocol
-
-from . import _types as _t
 from .utils import function_has_arg
 from .utils import trace
 from .version import ScmVersion
 
 if TYPE_CHECKING:
     from .config import Configuration
+    from typing_extensions import Protocol
+    from . import _types as _t
 else:
     Configuration = Any
 
+    class Protocol:
+        pass
+
 
 class MaybeConfigFunction(Protocol):
     __name__: str
@@ -71,7 +73,17 @@ def _version_from_entrypoints(
 try:
     from importlib.metadata import entry_points  # type: ignore
 except ImportError:
-    from importlib_metadata import entry_points
+    try:
+        from importlib_metadata import entry_points
+    except ImportError:
+        from collections import defaultdict
+
+        def entry_points() -> dict[str, list[_t.EntrypointProtocol]]:
+            warnings.warn(
+                "importlib metadata missing, "
+                "this may happen at build time for python3.7"
+            )
+            return defaultdict(list)
 
 
 def iter_entry_points(

src/setuptools_scm/_types.py

@@ -3,7 +3,6 @@
 from typing import Any
 from typing import Callable
 from typing import List
-from typing import NamedTuple
 from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
@@ -22,12 +21,6 @@
 VERSION_SCHEME = Union[str, Callable[["version.ScmVersion"], str]]
 
 
-class CmdResult(NamedTuple):
-    out: str
-    err: str
-    returncode: int
-
-
 class EntrypointProtocol(Protocol):
     name: str
 

src/setuptools_scm/config.py

@@ -12,13 +12,13 @@
 from typing import TYPE_CHECKING
 from typing import Union
 
-from . import _types as _t
 from ._version_cls import NonNormalizedVersion
 from ._version_cls import Version
 from .utils import trace
 
 
 if TYPE_CHECKING:
+    from . import _types as _t
     from setuptools_scm.version import ScmVersion
 
 DEFAULT_TAG_REGEX = r"^(?:[\w-]+-)?(?P<version>[vV]?\d+(?:\.\d+){0,2}[^\+]*)(?:\+.*)?$"

src/setuptools_scm/discover.py

@@ -3,8 +3,10 @@
 import os
 from typing import Iterable
 from typing import Iterator
+from typing import TYPE_CHECKING
 
-from . import _types as _t
+if TYPE_CHECKING:
+    from . import _types as _t
 from .config import Configuration
 from .utils import trace
 

src/setuptools_scm/git.py

@@ -11,9 +11,9 @@
 from typing import Callable
 from typing import TYPE_CHECKING
 
-from . import _types as _t
 from .config import Configuration
 from .scm_workdir import Workdir
+from .utils import _CmdResult
 from .utils import data_from_mime
 from .utils import do_ex
 from .utils import require_command
@@ -23,6 +23,8 @@
 from .version import tags_to_versions
 
 if TYPE_CHECKING:
+    from . import _types as _t
+
     from setuptools_scm.hg_git import GitWorkdirHgClient
 
 REF_TAG_RE = re.compile(r"(?<=\btag: )([^,]+)\b")
@@ -72,7 +74,7 @@ def from_potential_worktree(cls, wd: _t.PathT) -> GitWorkdir | None:
 
         return cls(real_wd)
 
-    def do_ex_git(self, cmd: list[str]) -> _t.CmdResult:
+    def do_ex_git(self, cmd: list[str]) -> _CmdResult:
         return self.do_ex(["git", "--git-dir", join(self.path, ".git")] + cmd)
 
     def is_dirty(self) -> bool:
@@ -120,7 +122,7 @@ def count_all_nodes(self) -> int:
         revs, _, _ = self.do_ex_git(["rev-list", "HEAD"])
         return revs.count("\n") + 1
 
-    def default_describe(self) -> _t.CmdResult:
+    def default_describe(self) -> _CmdResult:
         git_dir = join(self.path, ".git")
         return self.do_ex(
             DEFAULT_DESCRIBE[:1] + ["--git-dir", git_dir] + DEFAULT_DESCRIBE[1:]

src/setuptools_scm/hacks.py

@@ -1,8 +1,10 @@
 from __future__ import annotations
 
 import os
+from typing import TYPE_CHECKING
 
-from . import _types as _t
+if TYPE_CHECKING:
+    from . import _types as _t
 from .config import Configuration
 from .utils import data_from_mime
 from .utils import trace

src/setuptools_scm/hg.py

@@ -3,8 +3,8 @@
 import datetime
 import os
 from pathlib import Path
+from typing import TYPE_CHECKING
 
-from . import _types as _t
 from ._version_cls import Version
 from .config import Configuration
 from .scm_workdir import Workdir
@@ -16,6 +16,9 @@
 from .version import ScmVersion
 from .version import tag_to_version
 
+if TYPE_CHECKING:
+    from . import _types as _t
+
 
 class HgWorkdir(Workdir):
 

src/setuptools_scm/hg_git.py

@@ -8,12 +8,13 @@
 from . import _types as _t
 from .git import GitWorkdir
 from .hg import HgWorkdir
+from .utils import _CmdResult
 from .utils import do_ex
 from .utils import require_command
 from .utils import trace
 
 
-_FAKE_GIT_DESCRIBE_ERROR = _t.CmdResult("<>hg git failed", "", 1)
+_FAKE_GIT_DESCRIBE_ERROR = _CmdResult("<>hg git failed", "", 1)
 
 
 class GitWorkdirHgClient(GitWorkdir, HgWorkdir):
@@ -94,7 +95,7 @@ def count_all_nodes(self) -> int:
         revs, _, _ = self.do_ex(["hg", "log", "-r", "ancestors(.)", "-T", "."])
         return len(revs)
 
-    def default_describe(self) -> _t.CmdResult:
+    def default_describe(self) -> _CmdResult:
         """
         Tentative to reproduce the output of
 
@@ -142,4 +143,4 @@ def default_describe(self) -> _t.CmdResult:
         if self.is_dirty():
             desc += "-dirty"
         trace("desc", desc)
-        return _t.CmdResult(desc, "", 0)
+        return _CmdResult(desc, "", 0)