Merge bitcoin/bitcoin#27483: Bump python minimum version to 3.8

fac395e ci: Bump ci/lint/Dockerfile (MarcoFalke)
fa6eb65 test: Use python3.8 pow() (MarcoFalke)
88881cf Bump python minimum version to 3.8 (MarcoFalke)

Pull request description:

  There is no pressing reason to drop support for 3.7, however there are several maintenance issues:

  * There is no supported operating system that ships 3.7 by default. (debian:buster is EOL and unmaintained to the extent that it doesn't run in the CI environment. See bitcoin/bitcoin#27340 (comment))
  * Compiling python 3.7 from source is also unsupported on at least macos, according to bitcoin/bitcoin#24017 (comment)
  * Recent versions of lief require 3.8, see bitcoin/bitcoin#27507 (comment)

  Fix all maintenance issues by bumping the minimum.

ACKs for top commit:
  RandyMcMillan:
    ACK fac395e
  fjahr:
    ACK fac395e
  fanquake:
    ACK fac395e

Tree-SHA512: c198decdbbe29d186d73ea3f6549d8a38479383495d14a965a2f9211ce39637b43f13a4c2a5d3bf56e2d468be4bbe49b4ee8e8e19ec69936ff43ddf2b714c712

.cirrus.yml

@@ -228,7 +228,7 @@ task:
     PACKAGE_MANAGER_INSTALL: "yum install -y"
 
 task:
-  name: '[previous releases, uses qt5 dev package and some depends packages, DEBUG] [unsigned char] [buster]'
+  name: '[previous releases, qt5 dev package and depends packages, DEBUG] [focal]'
   previous_releases_cache:
     folder: "releases"
   << : *GLOBAL_TASK_TEMPLATE

.python-version

@@ -1 +1 @@
-3.7.16
+3.8.16

ci/lint/Dockerfile

@@ -5,7 +5,7 @@
 # entire repo as docker context during build; if it lived elsewhere, it wouldn't be
 # able to make back-references to pull in the install scripts. So here it lives.
 
-FROM python:3.7-buster
+FROM python:3.8-buster
 
 ENV DEBIAN_FRONTEND=noninteractive
 ENV LC_ALL=C.UTF-8

ci/test/00_setup_env_i686_centos.sh

@@ -8,7 +8,8 @@ export LC_ALL=C.UTF-8
 
 export HOST=i686-pc-linux-gnu
 export CONTAINER_NAME=ci_i686_centos
-export CI_IMAGE_NAME_TAG=quay.io/centos/centos:stream8
+export CI_IMAGE_NAME_TAG="quay.io/centos/centos:stream8"
+# Use minimum supported python3.8 and gcc-8, see doc/dependencies.md
 export CI_BASE_PACKAGES="gcc-c++ glibc-devel.x86_64 libstdc++-devel.x86_64 glibc-devel.i686 libstdc++-devel.i686 ccache libtool make git python38 python38-pip which patch lbzip2 xz procps-ng dash rsync coreutils bison"
 export PIP_PACKAGES="pyzmq"
 export GOAL="install"

ci/test/00_setup_env_native_nowallet_libbitcoinkernel.sh

@@ -7,8 +7,8 @@
 export LC_ALL=C.UTF-8
 
 export CONTAINER_NAME=ci_native_nowallet_libbitcoinkernel
-export CI_IMAGE_NAME_TAG=ubuntu:focal
-# Use minimum supported python3.7 (or python3.8, as best-effort) and clang-8, see doc/dependencies.md
+export CI_IMAGE_NAME_TAG="ubuntu:20.04"
+# Use minimum supported python3.8 and clang-8, see doc/dependencies.md
 export PACKAGES="python3-zmq clang-8 llvm-8 libc++abi-8-dev libc++-8-dev"
 export DEP_OPTS="NO_WALLET=1 CC=clang-8 CXX='clang++-8 -stdlib=libc++'"
 export GOAL="install"

ci/test/00_setup_env_native_qt5.sh

@@ -7,15 +7,15 @@
 export LC_ALL=C.UTF-8
 
 export CONTAINER_NAME=ci_native_qt5
-export CI_IMAGE_NAME_TAG=debian:buster
-# Use minimum supported python3.7 and gcc-8, see doc/dependencies.md
-export PACKAGES="gcc-8 g++-8 python3-zmq qtbase5-dev qttools5-dev-tools libdbus-1-dev libharfbuzz-dev"
-export DEP_OPTS="NO_QT=1 NO_UPNP=1 NO_NATPMP=1 DEBUG=1 ALLOW_HOST_PACKAGES=1 CC=gcc-8 CXX=g++-8"
+export CI_IMAGE_NAME_TAG="ubuntu:20.04"
+# Use minimum supported python3.8 and gcc-8 (or best-effort gcc-9), see doc/dependencies.md
+export PACKAGES="gcc-9 g++-9 python3-zmq qtbase5-dev qttools5-dev-tools libdbus-1-dev libharfbuzz-dev"
+export DEP_OPTS="NO_QT=1 NO_UPNP=1 NO_NATPMP=1 DEBUG=1 ALLOW_HOST_PACKAGES=1 CC=gcc-9 CXX=g++-9"
 export TEST_RUNNER_EXTRA="--previous-releases --coverage --extended --exclude feature_dbcrash"  # Run extended tests so that coverage does not fail, but exclude the very slow dbcrash
 export RUN_UNIT_TESTS_SEQUENTIAL="true"
 export RUN_UNIT_TESTS="false"
 export GOAL="install"
 export NO_WERROR=1
 export DOWNLOAD_PREVIOUS_RELEASES="true"
 export BITCOIN_CONFIG="--enable-zmq --with-libs=no --with-gui=qt5 --enable-reduce-exports \
---enable-debug CFLAGS=\"-g0 -O2 -funsigned-char\" CXXFLAGS=\"-g0 -O2 -funsigned-char\" CC=gcc-8 CXX=g++-8"
+--enable-debug CFLAGS=\"-g0 -O2 -funsigned-char\" CXXFLAGS=\"-g0 -O2 -funsigned-char\""

configure.ac

@@ -126,8 +126,8 @@ AC_PATH_TOOL([AR], [ar])
 AC_PATH_TOOL([GCOV], [gcov])
 AC_PATH_TOOL([LLVM_COV], [llvm-cov])
 AC_PATH_PROG([LCOV], [lcov])
-dnl Python 3.7 is specified in .python-version and should be used if available, see doc/dependencies.md
-AC_PATH_PROGS([PYTHON], [python3.7 python3.8 python3.9 python3.10 python3.11 python3.12 python3 python])
+dnl Python 3.8 is specified in .python-version and should be used if available, see doc/dependencies.md
+AC_PATH_PROGS([PYTHON], [python3.8 python3.9 python3.10 python3.11 python3.12 python3 python])
 AC_PATH_PROG([GENHTML], [genhtml])
 AC_PATH_PROG([GIT], [git])
 AC_PATH_PROG([CCACHE], [ccache])

doc/dependencies.md

@@ -10,7 +10,7 @@ You can find installation instructions in the `build-*.md` file for your platfor
 | [Automake](https://www.gnu.org/software/automake/) | [1.13](https://github.com/bitcoin/bitcoin/pull/18290) |
 | [Clang](https://clang.llvm.org) | [8.0](https://github.com/bitcoin/bitcoin/pull/24164) |
 | [GCC](https://gcc.gnu.org) | [8.1](https://github.com/bitcoin/bitcoin/pull/23060) |
-| [Python](https://www.python.org) (tests) | [3.7](https://github.com/bitcoin/bitcoin/pull/26226) |
+| [Python](https://www.python.org) (scripts, tests) | [3.8](https://github.com/bitcoin/bitcoin/pull/27483) |
 | [systemtap](https://sourceware.org/systemtap/) ([tracing](tracing.md))| N/A |
 
 ## Required

test/functional/test_framework/util.py

@@ -542,18 +542,7 @@ def modinv(a, n):
     """Compute the modular inverse of a modulo n using the extended Euclidean
     Algorithm. See https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm#Modular_integers.
     """
-    # TODO: Change to pow(a, -1, n) available in Python 3.8
-    t1, t2 = 0, 1
-    r1, r2 = n, a
-    while r2 != 0:
-        q = r1 // r2
-        t1, t2 = t2, t1 - q * t2
-        r1, r2 = r2, r1 - q * r2
-    if r1 > 1:
-        return None
-    if t1 < 0:
-        t1 += n
-    return t1
+    return pow(a, -1, n)
 
 class TestFrameworkUtil(unittest.TestCase):
     def test_modinv(self):