Drop support for Python 3.6

Python 3.6 reached its upstream EOL in September 2021, and was last
included in CentOS Stream 8 and Ubuntu 18.04 LTS (Bionic) which are
also both well past their EOL. This allows us to do some cleanup in
how bindep is packaged, since PEP 517 and its successors weren't
really well supported until versions of tools that have themselves
dropped support for 3.6.

Retain testing on ubuntu-bionic nodes for now, since there's
non-default Python 3.7 packaged on them, as the only platform we
presently have which meets that requirement for our new lower bound.

Change-Id: I0945465b63e4a8654c735786b3e3cf794c763741

.zuul.yaml

@@ -15,11 +15,6 @@
     parent: bindep-base
     nodeset: centos-9-stream
 
-- job:
-    name: bindep-ubuntu-bionic
-    parent: bindep-base
-    nodeset: ubuntu-bionic
-
 - job:
     name: bindep-ubuntu-noble
     parent: bindep-base
@@ -33,11 +28,10 @@
     check:
       jobs:
         - bindep-centos-9-stream
-        - bindep-ubuntu-bionic
         - bindep-ubuntu-noble
         - build-python-release
         - nox-linters
-        - nox-py36:
+        - nox-py37:
             nodeset: ubuntu-bionic
         - nox-py312:
             nodeset: ubuntu-noble
@@ -45,11 +39,10 @@
     gate:
       jobs:
         - bindep-centos-9-stream
-        - bindep-ubuntu-bionic
         - bindep-ubuntu-noble
         - build-python-release
         - nox-linters
-        - nox-py36:
+        - nox-py37:
             nodeset: ubuntu-bionic
         - nox-py312:
             nodeset: ubuntu-noble

noxfile.py

@@ -32,11 +32,7 @@ def docs(session):
 def venv(session):
     session.install("-r", "requirements.txt")
     session.install("-r", "test-requirements.txt")
-    # TODO: clean this conditional up once Python 3.6 support is dropped
-    if session.python == "3.6":
-        session.install(".")
-    else:
-        session.install("-e", ".")
+    session.install("-e", ".")
     session.run(*session.posargs)
 
 
@@ -45,11 +41,7 @@ def venv(session):
 def tests(session):
     session.install("-r", "requirements.txt")
     session.install("-r", "test-requirements.txt")
-    # TODO: clean this conditional up once Python 3.6 support is dropped
-    if session.python == "3.6":
-        session.install(".")
-    else:
-        session.install("-e", ".")
+    session.install("-e", ".")
     session.run("stestr", "run", *session.posargs)
     session.run("stestr", "slowest")
 
@@ -58,11 +50,7 @@ def tests(session):
 def cover(session):
     session.install("-r", "requirements.txt")
     session.install("-r", "test-requirements.txt")
-    # TODO: clean this conditional up once Python 3.6 support is dropped
-    if session.python == "3.6":
-        session.install(".")
-    else:
-        session.install("-e", ".")
+    session.install("-e", ".")
     session.env["PYTHON"] = "coverage run --source bindep --parallel-mode"
     session.run("stestr", "run", *session.posargs)
     session.run("stestr", "slowest")

pyproject.toml

@@ -16,7 +16,6 @@ classifiers = [
     "Operating System :: MacOS :: MacOS X",
     "Operating System :: POSIX :: Linux",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
@@ -48,7 +47,7 @@ maintainers = [
 ]
 name = "bindep"
 readme = {charset = "UTF-8", content-type = "text/x-rst", file = "README.rst"}
-requires-python = ">=3.6"
+requires-python = ">=3.7"
 
 [project.scripts]
 bindep = "bindep.__main__:main"

releasenotes/notes/drop-py36-c2684ca4e7ac758f.yaml

@@ -0,0 +1,3 @@
+---
+upgrade:
+  - Python 3.6 is no longer supported.

setup.cfg

@@ -1,12 +1,3 @@
-# TODO: Drop this section once PBR can read project names from pyproject.toml
+# TODO: Delete this file once PBR can read project names from pyproject.toml
 [metadata]
 name = bindep
-
-# TODO: Drop this section once we no longer support Python 3.6
-[options]
-py_modules = bindep
-
-# TODO: Drop this section once we no longer support Python 3.6
-[entry_points]
-console_scripts =
-    bindep = bindep.__main__:main