define own build backend

this removes setup.py altogether in turn preventing legacy usage

5 files changed, 68 insertions, 67 deletions

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index ced36e7..c32c140 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -22,6 +22,7 @@ repos:
     rev: 6.0.0
     hooks:
     -   id: flake8
+        exclude: scm_hack_build_backend.py
 -   repo: https://github.com/asottile/pyupgrade
     rev: v3.3.1
     hooks:
diff --git a/pyproject.toml b/pyproject.toml
index 93a1e44..7632fdb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,10 +1,13 @@
 [build-system]
-build-backend = "setuptools.build_meta"
+build-backend = "scm_hack_build_backend"
 requires = [
   "packaging>=20",
   "setuptools>=55",
   "typing_extensions",
 ]
+backend-path = [
+  ".",
+]
 
 [project]
 name = "setuptools-scm"
@@ -90,5 +93,8 @@ pip-egg-info = "setuptools_scm.hacks:parse_pip_egg_info"
 
 
 
+[tool.setuptools.dynamic]
+version = {attr = "scm_hack_build_backend.dynamic_version"}
+
 [tool.setuptools.packages.find]
 where = ["src"]
diff --git a/scm_hack_build_backend.py b/scm_hack_build_backend.py
new file mode 100644
index 0000000..08c8fae
--- /dev/null
+++ b/scm_hack_build_backend.py
@@ -0,0 +1,60 @@
+"""
+this module is a hack only in place to allow for setuptools
+to use the attribute for the versions
+"""
+from __future__ import annotations
+
+import os
+import sys
+from pathlib import Path
+
+root = Path(__file__).parent
+sys.path.insert(0, os.fspath(root / "src"))
+
+from setuptools.build_meta import (  # type: ignore[attr-defined]
+    get_requires_for_build_wheel,
+    get_requires_for_build_sdist,
+    prepare_metadata_for_build_wheel,
+    build_wheel,
+    build_sdist,
+    get_requires_for_build_editable,
+    prepare_metadata_for_build_editable,
+    build_editable,
+)
+
+
+from setuptools_scm import get_version
+from setuptools_scm.hacks import parse_pkginfo
+from setuptools_scm import git
+from setuptools_scm import hg
+from setuptools_scm.version import guess_next_dev_version, get_local_node_and_date
+from setuptools_scm import Configuration
+
+from setuptools_scm.version import ScmVersion
+
+
+dynamic_version: str
+
+
+def parse(root: str, config: Configuration) -> ScmVersion | None:
+    try:
+        return parse_pkginfo(root, config)
+    except OSError:
+        return git.parse(root, config=config) or hg.parse(root, config=config)
+
+
+def scm_version() -> str:
+    return get_version(
+        root=str(root),
+        parse=parse,
+        version_scheme=guess_next_dev_version,
+        local_scheme=get_local_node_and_date,
+    )
+
+
+def __getattr__(name: str) -> str:
+    if name == "dynamic_version":
+        global dynamic_version
+        dynamic_version = scm_version()
+        return dynamic_version
+    raise AttributeError(name)
diff --git a/setup.py b/setup.py
deleted file mode 100644
index e8e69bc..0000000
--- a/setup.py
+++ /dev/null
@@ -1,58 +0,0 @@
-"""\
-important note:
-
-the setup of setuptools_scm is self-using,
-the first execution of `python setup.py egg_info`
-will generate partial data
-It's critical to run `python setup.py egg_info`
-once before running sdist or easy_install on a fresh checkouts
-
-pip usage is recommended
-"""
-from __future__ import annotations
-
-import os
-import sys
-
-import setuptools
-
-
-def scm_version() -> str:
-    here = os.path.dirname(os.path.abspath(__file__))
-    src = os.path.join(here, "src")
-
-    sys.path.insert(0, src)
-
-    from setuptools_scm import get_version
-    from setuptools_scm.hacks import parse_pkginfo
-    from setuptools_scm import git
-    from setuptools_scm import hg
-    from setuptools_scm.version import guess_next_dev_version, get_local_node_and_date
-    from setuptools_scm import Configuration
-
-    from setuptools_scm.version import ScmVersion
-
-    def parse(root: str, config: Configuration) -> ScmVersion | None:
-        try:
-            return parse_pkginfo(root, config)
-        except OSError:
-            return git.parse(root, config=config) or hg.parse(root, config=config)
-
-    return get_version(
-        root=here,
-        parse=parse,
-        version_scheme=guess_next_dev_version,
-        local_scheme=get_local_node_and_date,
-    )
-
-
-if __name__ == "__main__":
-    setuptools.setup(
-        version=scm_version(),
-        extras_require={
-            "toml": [
-                "setuptools>=42",
-            ],
-            "test": ["pytest>=6.2", "virtualenv>20"],
-        },
-    )
diff --git a/testing/check_self_install.py b/testing/check_self_install.py
deleted file mode 100644
index 0cfab33..0000000
--- a/testing/check_self_install.py
+++ /dev/null
@@ -1,8 +0,0 @@
-from __future__ import annotations
-
-import pkg_resources
-
-import setuptools_scm
-
-dist = pkg_resources.get_distribution("setuptools_scm")
-assert dist.version == setuptools_scm.get_version(), dist.version