From 362fd291e1cf04cbbf9e3adc7c986450a156a8c2 Mon Sep 17 00:00:00 2001
From: Remco de Boer <29308176+redeboer@users.noreply.github.com>
Date: Tue, 3 Oct 2023 18:50:11 +0200
Subject: [PATCH] FIX: downgrade `setuptools` for lower versions of Python

---
 pyproject.toml                          |  2 +-
 src/repoma/check_dev_files/setup_cfg.py | 25 +++++++++++++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 7fe5002a..3a207f85 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [build-system]
 build-backend = "setuptools.build_meta"
 requires = [
-    "setuptools>=61.2",
+    "setuptools>=58.0",
     "setuptools_scm",
 ]
 
diff --git a/src/repoma/check_dev_files/setup_cfg.py b/src/repoma/check_dev_files/setup_cfg.py
index 26e5fb23..89119900 100644
--- a/src/repoma/check_dev_files/setup_cfg.py
+++ b/src/repoma/check_dev_files/setup_cfg.py
@@ -6,7 +6,7 @@
 import textwrap
 from collections import defaultdict
 from configparser import RawConfigParser
-from typing import Dict, List, Tuple, Union
+from typing import Dict, List, Optional, Tuple, Union
 
 import tomlkit
 from ini2toml.api import Translator
@@ -18,7 +18,7 @@
 from repoma.utilities import CONFIG_PATH
 from repoma.utilities.executor import Executor
 from repoma.utilities.precommit import remove_precommit_hook
-from repoma.utilities.project_info import get_pypi_name
+from repoma.utilities.project_info import get_pypi_name, get_supported_python_versions
 from repoma.utilities.pyproject import (
     get_sub_table,
     load_pyproject,
@@ -50,6 +50,8 @@ def _convert_to_pyproject() -> None:
     extras_require = _get_recursive_optional_dependencies()
     if extras_require:
         _update_optional_dependencies(pyproject, extras_require)
+    if "3.6" in get_supported_python_versions(pyproject):
+        __downgrade_setuptools(pyproject)
     write_pyproject(pyproject)
     os.remove(setup_cfg)
     if os.path.exists("setup.py"):
@@ -59,6 +61,25 @@ def _convert_to_pyproject() -> None:
     raise PrecommitError(msg)
 
 
+def __downgrade_setuptools(pyproject: TOMLDocument) -> None:
+    if "3.6" not in get_supported_python_versions(pyproject):
+        return
+    build_system: Optional[Table] = pyproject.get("build-system")
+    if build_system is None:
+        return
+    requirements: Optional[Array] = build_system.get("requires")
+    if requirements is None:
+        return
+    for idx, package in enumerate(requirements):
+        if ">" not in package:
+            continue
+        package, *_ = package.split(">")
+        if package.strip() == "setuptools":
+            requirements[idx] = "setuptools>=58.0"
+            break
+    build_system["requires"] = requirements
+
+
 def _get_recursive_optional_dependencies() -> Dict[str, List[Tuple[str, str]]]:
     if not CONFIG_PATH.setup_cfg.exists():
         return {}