Add, use tools/describe script

This isn't intended to make any overt behavioral change, but
there is a slight one in the value of CP_VERSION that will be used
during CI, because it will now include `--always --match "..."`,
so there could be a change to the uploaded name of the mpy-cross
artifacts on s3.

.github/workflows/build.yml

@@ -38,8 +38,8 @@ jobs:
       run: python tools/ci_fetch_deps.py test ${{ github.sha }}
     - name: CircuitPython version
       run: |
-        git describe --dirty --tags || git log --parents HEAD~4..
-        echo >>$GITHUB_ENV CP_VERSION=$(git describe --dirty --tags)
+        tools/describe || git log --parents HEAD~4..
+        echo >>$GITHUB_ENV CP_VERSION=$(tools/describe)
     - name: Install dependencies
       run: |
         sudo apt-get update
@@ -144,8 +144,8 @@ jobs:
       run: python tools/ci_fetch_deps.py mpy-cross-mac ${{ github.sha }}
     - name: CircuitPython version
       run: |
-        git describe --dirty --tags
-        echo >>$GITHUB_ENV CP_VERSION=$(git describe --dirty --tags)
+        tools/describe || git log --parents HEAD~4..
+        echo >>$GITHUB_ENV CP_VERSION=$(tools/describe)
     - name: Install dependencies
       run: |
         brew install gettext
@@ -200,8 +200,8 @@ jobs:
       run: python tools/ci_fetch_deps.py docs ${{ github.sha }}
     - name: CircuitPython version
       run: |
-        git describe --dirty --tags
-        echo >>$GITHUB_ENV CP_VERSION=$(git describe --dirty --tags)
+        tools/describe || git log --parents HEAD~4..
+        echo >>$GITHUB_ENV CP_VERSION=$(tools/describe)
     - name: Set up Python 3
       uses: actions/setup-python@v2
       with:
@@ -375,7 +375,9 @@ jobs:
     - name: Get CP deps
       run: python tools/ci_fetch_deps.py ${{ matrix.board }} ${{ github.sha }}
     - name: CircuitPython version
-      run: git describe --dirty --tags
+      run: |
+        tools/describe || git log --parents HEAD~4..
+        echo >>$GITHUB_ENV CP_VERSION=$(tools/describe)
     - uses: actions/cache@v2
       name: Fetch IDF tool cache
       id: idf-cache

.github/workflows/create_website_pr.yml

@@ -34,7 +34,9 @@ jobs:
         gcc --version
         python3 --version
     - name: CircuitPython version
-      run: git describe --dirty --tags
+      run: |
+        tools/describe || git log --parents HEAD~4..
+        echo >>$GITHUB_ENV CP_VERSION=$(tools/describe)
     - name: Website
       run: python3 build_board_info.py
       working-directory: tools

.github/workflows/ports_windows.yml

@@ -73,8 +73,8 @@ jobs:
       run: python tools/ci_fetch_deps.py windows ${{ github.sha }}
     - name: CircuitPython version
       run: |
-        git describe --dirty --tags
-        echo >>$GITHUB_ENV CP_VERSION=$(git describe --dirty --tags)
+        tools/describe || git log --parents HEAD~4..
+        echo >>$GITHUB_ENV CP_VERSION=$(tools/describe)
 
     - name: build mpy-cross
       run: make -j2 -C mpy-cross

conf.py

@@ -24,12 +24,15 @@ import subprocess
 import sys
 import urllib.parse
 import time
+import pathlib
 from collections import defaultdict
 
 from sphinx.transforms import SphinxTransform
 from docutils import nodes
 from sphinx import addnodes
 
+tools_describe = (pathlib.Path(__file__).parent / "tools/describe").str()
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
@@ -129,7 +132,7 @@ copyright = f'2014-{current_date.tm_year}, MicroPython & CircuitPython contribut
 
 final_version = ""
 git_describe = subprocess.run(
-    ["git", "describe", "--dirty", "--tags"],
+    [tools_describe],
     stdout=subprocess.PIPE,
     stderr=subprocess.STDOUT,
     encoding="utf-8"

py/makeversionhdr.py

@@ -1,29 +1,25 @@
 """
 Generate header file with macros defining MicroPython version info.
 
-This script works with Python 2.6, 2.7, 3.3 and 3.4.
+This script works with Python 3.7 and newer
 """
 
 from __future__ import print_function
 
 import sys
 import os
+import pathlib
 import datetime
 import subprocess
 
+tools_describe = str(pathlib.Path(__file__).parent.parent / "tools/describe")
+
 
 def get_version_info_from_git():
-    # Python 2.6 doesn't have check_output, so check for that
-    try:
-        subprocess.check_output
-        subprocess.check_call
-    except AttributeError:
-        return None
-
     # Note: git describe doesn't work if no tag is available
     try:
         git_tag = subprocess.check_output(
-            ["git", "describe", "--tags", "--dirty", "--always", "--match", "[1-9].*"],
+            [tools_describe],
             stderr=subprocess.STDOUT,
             universal_newlines=True,
         ).strip()

tools/describe

@@ -0,0 +1,2 @@
+#!/bin/sh
+git describe --dirty --tags --always --match "[1-9].*"