Bump minimum python version to 3.7

.cirrus.yml

@@ -295,10 +295,10 @@ task:
     FILE_ENV: "./ci/test/00_setup_env_i686_multiprocess.sh"
 
 task:
-  name: '[no wallet, libbitcoinkernel] [bionic]'
+  name: '[no wallet, libbitcoinkernel] [buster]'
   << : *GLOBAL_TASK_TEMPLATE
   container:
-    image: ubuntu:bionic
+    image: debian:buster
   env:
     << : *CIRRUS_EPHEMERAL_WORKER_TEMPLATE_ENV
     FILE_ENV: "./ci/test/00_setup_env_native_nowallet_libbitcoinkernel.sh"

.python-version

@@ -1 +1 @@
-3.6.15
+3.7.16

ci/test/00_setup_env_i686_centos.sh

@@ -9,7 +9,7 @@ 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_BASE_PACKAGES="gcc-c++ glibc-devel.x86_64 libstdc++-devel.x86_64 glibc-devel.i686 libstdc++-devel.i686 ccache libtool make git python3 python3-pip which patch lbzip2 xz procps-ng dash rsync coreutils bison"
+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"
 export BITCOIN_CONFIG="--enable-zmq --with-gui=qt5 --enable-reduce-exports"

ci/test/00_setup_env_native_nowallet_libbitcoinkernel.sh

@@ -7,8 +7,10 @@
 export LC_ALL=C.UTF-8
 
 export CONTAINER_NAME=ci_native_nowallet_libbitcoinkernel
-export CI_IMAGE_NAME_TAG=ubuntu:18.04  # Use bionic to have one config run the tests in python3.6, see doc/dependencies.md
-export PACKAGES="python3-zmq clang-8 llvm-8 libc++abi-8-dev libc++-8-dev"  # Use clang-8 to test C++17 compatibility, see doc/dependencies.md
+export CI_IMAGE_NAME_TAG=debian:buster
+# Use minimum supported python3.7 and clang-8, see doc/dependencies.md
+export PACKAGES="-t buster-backports python3-zmq clang-8 llvm-8 libc++abi-8-dev libc++-8-dev"
+export APPEND_APT_SOURCES_LIST="deb http://deb.debian.org/debian buster-backports main"
 export DEP_OPTS="NO_WALLET=1 CC=clang-8 CXX='clang++-8 -stdlib=libc++'"
 export GOAL="install"
 export BITCOIN_CONFIG="--enable-reduce-exports CC=clang-8 CXX='clang++-8 -stdlib=libc++' --enable-experimental-util-chainstate --with-experimental-kernel-lib --enable-shared"

ci/test/00_setup_env_native_qt5.sh

@@ -7,7 +7,8 @@
 export LC_ALL=C.UTF-8
 
 export CONTAINER_NAME=ci_native_qt5
-export CI_IMAGE_NAME_TAG=debian:buster  # Check that buster gcc-8 can compile our C++17 and run our functional tests in python3, see doc/dependencies.md
+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 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

ci/test/04_install.sh

@@ -92,6 +92,9 @@ elif [ "$CI_USE_APT_INSTALL" != "no" ]; then
     # TODO: drop this once we can use newer images in GCE
     CI_EXEC_ROOT add-apt-repository ppa:hadret/bpfcc
   fi
+  if [[ -n "${APPEND_APT_SOURCES_LIST}" ]]; then
+    CI_EXEC_ROOT echo "${APPEND_APT_SOURCES_LIST}" >> /etc/apt/sources.list
+  fi
   ${CI_RETRY_EXE} CI_EXEC_ROOT apt-get update
   ${CI_RETRY_EXE} CI_EXEC_ROOT apt-get install --no-install-recommends --no-upgrade -y "$PACKAGES" "$CI_BASE_PACKAGES"
 fi

configure.ac

@@ -120,8 +120,8 @@ AC_PATH_TOOL([AR], [ar])
 AC_PATH_TOOL([GCOV], [gcov])
 AC_PATH_TOOL([LLVM_COV], [llvm-cov])
 AC_PATH_PROG([LCOV], [lcov])
-dnl Python 3.6 is specified in .python-version and should be used if available, see doc/dependencies.md
-AC_PATH_PROGS([PYTHON], [python3.6 python3.7 python3.8 python3.9 python3.10 python3.11 python3 python])
+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])
 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) | [3.6](https://github.com/bitcoin/bitcoin/pull/19504) |
+| [Python](https://www.python.org) (tests) | [3.7](https://github.com/bitcoin/bitcoin/pull/26226) |
 | [systemtap](https://sourceware.org/systemtap/) ([tracing](tracing.md))| N/A |
 
 ## Required