Attempt to solve dependency resolution with Pipenv

src/pyscaffold/utils.py

@@ -314,10 +314,10 @@ def get_setup_requires_version():
     Returns:
         str: requirement string for setup_requires
     """
-    require_str = "pyscaffold>={major}.{minor}a0,<{major}.{next_minor}a0"
+    require_str = "pyscaffold>={major}.{minor}a0,<{next_major}"
     major, minor, *rest = parse_version(pyscaffold_version).base_version.split(".")
-    next_minor = int(minor) + 1
-    return require_str.format(major=major, minor=minor, next_minor=next_minor)
+    next_major = int(major) + 1
+    return require_str.format(major=major, minor=minor, next_major=next_major)
 
 
 def localize_path(path_string):

tests/system/test_dependency_managers.py

@@ -6,6 +6,7 @@
 
 import pytest
 
+from pyscaffold import __version__ as pyscaffold_version
 from pyscaffold.api import create_project
 
 pytestmark = [pytest.mark.slow, pytest.mark.system]
@@ -40,12 +41,18 @@ def test_pipenv_works_with_pyscaffold(cwd, venv_path, venv_run):
     # Given a project is created with pyscaffold
     # and it has some dependencies in setup.cfg
     create_project(project="myproj", requirements=["appdirs"])
+
+    if any(ch in pyscaffold_version for ch in ("b", "a", "pre", "rc")):
+        flags = "--pre"
+    else:
+        flags = ""
+
     with cwd.join("myproj").as_cwd():
         # When we install pipenv,
         venv_run("pip install -v pipenv")
         venv_run("pipenv --bare install certifi")
         # use it to proxy setup.cfg
-        venv_run("pipenv --bare install -e .")
+        venv_run("pipenv --bare install {} -e .".format(flags))
         # and install things to the dev env,
         venv_run("pipenv --bare install --dev flake8")