Drop support for Python 3.6.

.github/workflows/main.yaml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10', pypy3]
+        python-version: ['3.7', '3.8', '3.9', '3.10', pypy3]
     steps:
     - name: Check out source code
       uses: actions/checkout@v2

amaranth/_toolchain/cxx.py

@@ -19,7 +19,7 @@ def build_cxx(*, cxx_sources, output_name, include_dirs, macros):
 
         with warnings.catch_warnings():
             warnings.filterwarnings(action="ignore", category=DeprecationWarning)
-            # This emits a DeprecationWarning on Python 3.6 and 3.10.
+            # This emits a DeprecationWarning on Python 3.10.
             from setuptools import distutils
             cc_driver = distutils.ccompiler.new_compiler()
 

amaranth/_toolchain/yosys.py

@@ -12,14 +12,11 @@ except ImportError:
     except ImportError:
         importlib_metadata = None # not installed
 try:
+    from importlib import resources as importlib_resources
     try:
-        from importlib import resources as importlib_resources
+        importlib_resources.files # py3.9+ stdlib
-        try:
+    except AttributeError:
-            importlib_resources.files # py3.9+ stdlib
+        import importlib_resources # py3.8- shim
-        except AttributeError:
-            import importlib_resources # py3.8- shim
-    except ImportError:
-        import importlib_resources # py3.6- shim
 except ImportError:
     importlib_resources = None
 

docs/changes.rst

@@ -4,6 +4,12 @@ Changelog
 This document describes changes to the public interfaces in the Amaranth language and standard library. It does not include most bug fixes or implementation changes.
 
 
+Next version
+============
+
+Support for Python 3.6 has been dropped.
+
+
 Version 0.3
 ============
 

docs/install.rst

@@ -6,7 +6,7 @@ System requirements
 
 .. |yosys-version| replace:: 0.10 (or newer)
 
-Amaranth HDL requires Python 3.6; it works on CPython_ 3.6 (or newer), and works faster on PyPy3.6_ 7.2 (or newer).
+Amaranth HDL requires Python 3.7; it works on CPython_ 3.7 (or newer), and works faster on PyPy3.7_ 7.3.2 (or newer).
 
 For most workflows, Amaranth requires Yosys_ |yosys-version|. A compatible version of Yosys is distributed via PyPI_ for most popular platforms.
 
@@ -17,7 +17,7 @@ Synthesizing, placing and routing an Amaranth design for an FPGA requires the FP
 .. TODO: Link to FPGA family docs here
 
 .. _CPython: https://www.python.org/
-.. _PyPy3.6: https://www.pypy.org/
+.. _PyPy3.7: https://www.pypy.org/
 .. _Yosys: https://yosyshq.net/yosys/
 .. _PyPI: https://pypi.org/
 .. _GTKWave: http://gtkwave.sourceforge.net/

setup.py

@@ -37,7 +37,7 @@ setup(
     description="Amaranth hardware definition language",
     #long_description="""TODO""",
     license="BSD",
-    python_requires="~=3.6",
+    python_requires="~=3.7",
     setup_requires=["wheel", "setuptools", "setuptools_scm"],
     install_requires=[
         "importlib_metadata; python_version<'3.8'",  # for __version__ and amaranth._toolchain.yosys