Avoid impossible impossible minversion requirement

Fixes: #2414

Author: ssbarnea

docs/changelog/2414.bugfix.rst

@@ -0,0 +1 @@
+Avoid impossible minversion version requirements. - by :user:`ssbarnea`.

src/tox/provision.py

@@ -75,6 +75,14 @@ def provision(state: State) -> int | bool:
 
     def add_tox_requires_min_version(requires: list[Requirement]) -> list[Requirement]:
         min_version: Version = state.conf.core["min_version"]
+        # If own version can be a development one or a pre-release, we need to
+        # to only use its base_version for requirements, or pip will never be
+        # able to find a version that is compatible with the requirement.
+        # See https://github.com/tox-dev/tox/issues/2414
+        if min_version.is_devrelease or min_version.is_prerelease:  # noqa: SC200
+            # So we build a PEP 440 version out of the base ones.
+            # https://setuptools.pypa.io/en/latest/userguide/distribution.html#specifying-your-project-s-version
+            min_version = Version(min_version.base_version + "a0.dev0")
         requires.append(Requirement(f"tox >= {min_version.public}"))
         return requires