Merge bitcoin/bitcoin#26226: Bump minimum python version to 3.7

MarcoFalke · MarcoFalke · commit aef8b4f43b0c · 2023-01-18T16:46:12.000+01:00
fa8fe5b scripted-diff: Use new python 3.7 keywords (MarcoFalke) fa2a235 Revert "contrib: Fix capture_output in getcoins.py" (MarcoFalke) dddd462 Bump minimum python version to 3.7 (MarcoFalke) Pull request description: While there is nothing that requires a bump, it may require less maintenance to drop python3.6 support. Python3.7 is available through the package manager on all currently supported operating systems. ACKs for top commit: jamesob: ACK bitcoin/bitcoin@fa8fe5b hebasto: ACK fa8fe5b Tree-SHA512: f6e080d8751948bb0e01c87be601363158f345e8037b70ce7e1bc507c611eb61600e4f24f1d2f8a6e7e44877ab09319302869e33ce8118c4c4f71fc89c0a1198
diff --git a/.cirrus.yml b/.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"
diff --git a/.python-version b/.python-version
@@ -1 +1 @@
-3.6.15
+3.7.16
diff --git a/ci/test/00_setup_env_i686_centos.sh b/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"
diff --git a/ci/test/00_setup_env_native_nowallet_libbitcoinkernel.sh b/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"
diff --git a/ci/test/00_setup_env_native_qt5.sh b/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
diff --git a/ci/test/04_install.sh b/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
diff --git a/configure.ac b/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])
diff --git a/contrib/devtools/clang-format-diff.py b/contrib/devtools/clang-format-diff.py
@@ -146,7 +146,7 @@ def main():
                          stdout=subprocess.PIPE,
                          stderr=None,
                          stdin=subprocess.PIPE,
-                         universal_newlines=True)
+                         text=True)
     stdout, stderr = p.communicate()
     if p.returncode != 0:
       sys.exit(p.returncode)
diff --git a/contrib/devtools/gen-manpages.py b/contrib/devtools/gen-manpages.py
@@ -23,7 +23,7 @@
 # If not otherwise specified, get top directory from git.
 topdir = os.getenv('TOPDIR')
 if not topdir:
-    r = subprocess.run([git, 'rev-parse', '--show-toplevel'], stdout=subprocess.PIPE, check=True, universal_newlines=True)
+    r = subprocess.run([git, 'rev-parse', '--show-toplevel'], stdout=subprocess.PIPE, check=True, text=True)
     topdir = r.stdout.rstrip()
 
 # Get input and output directories.
@@ -36,7 +36,7 @@
 for relpath in BINARIES:
     abspath = os.path.join(builddir, relpath)
     try:
-        r = subprocess.run([abspath, "--version"], stdout=subprocess.PIPE, check=True, universal_newlines=True)
+        r = subprocess.run([abspath, "--version"], stdout=subprocess.PIPE, check=True, text=True)
     except IOError:
         print(f'{abspath} not found or not an executable', file=sys.stderr)
         sys.exit(1)
diff --git a/contrib/devtools/test-security-check.py b/contrib/devtools/test-security-check.py
@@ -39,7 +39,7 @@ def call_security_check(cc, source, executable, options):
         env_flags += filter(None, os.environ.get(var, '').split(' '))
 
     subprocess.run([*cc,source,'-o',executable] + env_flags + options, check=True)
-    p = subprocess.run([os.path.join(os.path.dirname(__file__), 'security-check.py'), executable], stdout=subprocess.PIPE, universal_newlines=True)
+    p = subprocess.run([os.path.join(os.path.dirname(__file__), 'security-check.py'), executable], stdout=subprocess.PIPE, text=True)
     return (p.returncode, p.stdout.rstrip())
 
 def get_arch(cc, source, executable):
diff --git a/contrib/devtools/test-symbol-check.py b/contrib/devtools/test-symbol-check.py
@@ -23,13 +23,13 @@ def call_symbol_check(cc: List[str], source, executable, options):
         env_flags += filter(None, os.environ.get(var, '').split(' '))
 
     subprocess.run([*cc,source,'-o',executable] + env_flags + options, check=True)
-    p = subprocess.run([os.path.join(os.path.dirname(__file__), 'symbol-check.py'), executable], stdout=subprocess.PIPE, universal_newlines=True)
+    p = subprocess.run([os.path.join(os.path.dirname(__file__), 'symbol-check.py'), executable], stdout=subprocess.PIPE, text=True)
     os.remove(source)
     os.remove(executable)
     return (p.returncode, p.stdout.rstrip())
 
 def get_machine(cc: List[str]):
-    p = subprocess.run([*cc,'-dumpmachine'], stdout=subprocess.PIPE, universal_newlines=True)
+    p = subprocess.run([*cc,'-dumpmachine'], stdout=subprocess.PIPE, text=True)
     return p.stdout.rstrip()
 
 class TestSymbolChecks(unittest.TestCase):
diff --git a/contrib/macdeploy/macdeployqtplus b/contrib/macdeploy/macdeployqtplus
@@ -187,7 +187,7 @@ def getFrameworks(binaryPath: str, verbose: int) -> List[FrameworkInfo]:
     if verbose:
         print(f"Inspecting with otool: {binaryPath}")
     otoolbin=os.getenv("OTOOL", "otool")
-    otool = run([otoolbin, "-L", binaryPath], stdout=PIPE, stderr=PIPE, universal_newlines=True)
+    otool = run([otoolbin, "-L", binaryPath], stdout=PIPE, stderr=PIPE, text=True)
     if otool.returncode != 0:
         sys.stderr.write(otool.stderr)
         sys.stderr.flush()
@@ -577,17 +577,17 @@ if config.dmg is not None:
 
     tempname: str = appname + ".temp.dmg"
 
-    run(["hdiutil", "create", tempname, "-srcfolder", "dist", "-format", "UDRW", "-size", str(size), "-volname", appname], check=True, universal_newlines=True)
+    run(["hdiutil", "create", tempname, "-srcfolder", "dist", "-format", "UDRW", "-size", str(size), "-volname", appname], check=True, text=True)
 
     if verbose:
         print("Attaching temp image...")
-    output = run(["hdiutil", "attach", tempname, "-readwrite"], check=True, universal_newlines=True, stdout=PIPE).stdout
+    output = run(["hdiutil", "attach", tempname, "-readwrite"], check=True, text=True, stdout=PIPE).stdout
 
     print("+ Finalizing .dmg disk image +")
 
-    run(["hdiutil", "detach", f"/Volumes/{appname}"], universal_newlines=True)
+    run(["hdiutil", "detach", f"/Volumes/{appname}"], text=True)
 
-    run(["hdiutil", "convert", tempname, "-format", "UDZO", "-o", appname, "-imagekey", "zlib-level=9"], check=True, universal_newlines=True)
+    run(["hdiutil", "convert", tempname, "-format", "UDZO", "-o", appname, "-imagekey", "zlib-level=9"], check=True, text=True)
 
     os.unlink(tempname)
 
diff --git a/contrib/signet/getcoins.py b/contrib/signet/getcoins.py
@@ -129,7 +129,7 @@ def bitcoin_cli(rpc_command_and_params):
 
     # Convert SVG image to PPM, and load it
     try:
-        rv = subprocess.run([args.imagemagick, 'svg:-', '-depth', '8', 'ppm:-'], input=res.content, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        rv = subprocess.run([args.imagemagick, 'svg:-', '-depth', '8', 'ppm:-'], input=res.content, check=True, capture_output=True)
     except FileNotFoundError:
         raise SystemExit(f"The binary {args.imagemagick} could not be found. Please make sure ImageMagick (or a compatible fork) is installed and that the correct path is specified.")
 
diff --git a/doc/dependencies.md b/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
diff --git a/test/functional/rpc_users.py b/test/functional/rpc_users.py
@@ -53,13 +53,13 @@ def setup_chain(self):
 
         # Generate RPCAUTH with specified password
         self.rt2password = "8/F3uMDw4KSEbw96U3CA1C4X05dkHDN2BPFjTgZW4KI="
-        p = subprocess.Popen([sys.executable, gen_rpcauth, 'rt2', self.rt2password], stdout=subprocess.PIPE, universal_newlines=True)
+        p = subprocess.Popen([sys.executable, gen_rpcauth, 'rt2', self.rt2password], stdout=subprocess.PIPE, text=True)
         lines = p.stdout.read().splitlines()
         rpcauth2 = lines[1]
 
         # Generate RPCAUTH without specifying password
         self.user = ''.join(SystemRandom().choice(string.ascii_letters + string.digits) for _ in range(10))
-        p = subprocess.Popen([sys.executable, gen_rpcauth, self.user], stdout=subprocess.PIPE, universal_newlines=True)
+        p = subprocess.Popen([sys.executable, gen_rpcauth, self.user], stdout=subprocess.PIPE, text=True)
         lines = p.stdout.read().splitlines()
         rpcauth3 = lines[1]
         self.password = lines[3]
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
@@ -730,7 +730,7 @@ def send_cli(self, command=None, *args, **kwargs):
             p_args += [command]
         p_args += pos_args + named_args
         self.log.debug("Running bitcoin-cli {}".format(p_args[2:]))
-        process = subprocess.Popen(p_args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
+        process = subprocess.Popen(p_args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
         cli_stdout, cli_stderr = process.communicate(input=self.input)
         returncode = process.poll()
         if returncode:
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
@@ -585,7 +585,7 @@ def run_tests(*, test_list, src_dir, build_dir, tmpdir, jobs=1, enable_coverage=
                     combined_logs_args = [sys.executable, os.path.join(tests_dir, 'combine_logs.py'), testdir]
                     if BOLD[0]:
                         combined_logs_args += ['--color']
-                    combined_logs, _ = subprocess.Popen(combined_logs_args, universal_newlines=True, stdout=subprocess.PIPE).communicate()
+                    combined_logs, _ = subprocess.Popen(combined_logs_args, text=True, stdout=subprocess.PIPE).communicate()
                     print("\n".join(deque(combined_logs.splitlines(), combined_logs_len)))
 
                 if failfast:
@@ -670,7 +670,7 @@ def get_next(self):
             self.jobs.append((test,
                               time.time(),
                               subprocess.Popen([sys.executable, self.tests_dir + test_argv[0]] + test_argv[1:] + self.flags + portseed_arg + tmpdir_arg,
-                                               universal_newlines=True,
+                                               text=True,
                                                stdout=log_stdout,
                                                stderr=log_stderr),
                               testdir,
diff --git a/test/functional/tool_wallet.py b/test/functional/tool_wallet.py
@@ -37,7 +37,7 @@ def bitcoin_wallet_process(self, *args):
         if not self.options.descriptors and 'create' in args:
             default_args.append('-legacy')
 
-        return subprocess.Popen([binary] + default_args + list(args), stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
+        return subprocess.Popen([binary] + default_args + list(args), stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
 
     def assert_raises_tool_error(self, error, *args):
         p = self.bitcoin_wallet_process(*args)
diff --git a/test/fuzz/test_runner.py b/test/fuzz/test_runner.py
@@ -143,7 +143,7 @@ def main():
             timeout=20,
             check=True,
             stderr=subprocess.PIPE,
-            universal_newlines=True,
+            text=True,
         ).stderr
         if "libFuzzer" not in help_output:
             logging.error("Must be built with libFuzzer")
@@ -200,7 +200,7 @@ def job(command, t):
                 env=get_fuzz_env(target=t, source_dir=src_dir),
                 check=True,
                 stderr=subprocess.PIPE,
-                universal_newlines=True,
+                text=True,
             ).stderr))
 
     futures = []
@@ -241,7 +241,7 @@ def job(t, args):
                 env=get_fuzz_env(target=t, source_dir=src_dir),
                 check=True,
                 stderr=subprocess.PIPE,
-                universal_newlines=True,
+                text=True,
             ).stderr
             logging.debug(output)
 
@@ -270,7 +270,7 @@ def job(t, args):
                 args,
                 env=get_fuzz_env(target=t, source_dir=src_dir),
                 stderr=subprocess.PIPE,
-                universal_newlines=True,
+                text=True,
             )
             output += result.stderr
             return output, result
@@ -299,7 +299,7 @@ def parse_test_list(*, fuzz_bin):
         },
         stdout=subprocess.PIPE,
         stderr=subprocess.DEVNULL,
-        universal_newlines=True,
+        text=True,
     ).stdout.splitlines()
     return test_list_all
 
diff --git a/test/lint/lint-assertions.py b/test/lint/lint-assertions.py
@@ -12,7 +12,7 @@
 
 def git_grep(params: [], error_msg: ""):
     try:
-        output = subprocess.check_output(["git", "grep", *params], universal_newlines=True, encoding="utf8")
+        output = subprocess.check_output(["git", "grep", *params], text=True, encoding="utf8")
         print(error_msg)
         print(output)
         return 1
diff --git a/test/lint/lint-circular-dependencies.py b/test/lint/lint-circular-dependencies.py
@@ -38,14 +38,14 @@ def main():
     os.chdir(CODE_DIR)
     files = subprocess.check_output(
         ['git', 'ls-files', '--', '*.h', '*.cpp'],
-        universal_newlines=True,
+        text=True,
     ).splitlines()
 
     command = [sys.executable, "../contrib/devtools/circular-dependencies.py", *files]
     dependencies_output = subprocess.run(
         command,
         stdout=subprocess.PIPE,
-        universal_newlines=True,
+        text=True,
     )
 
     for dependency_str in dependencies_output.stdout.rstrip().split("\n"):
diff --git a/test/lint/lint-git-commit-check.py b/test/lint/lint-git-commit-check.py
@@ -42,17 +42,17 @@ def main():
             commit_range = "HEAD~" + args.prev_commits + "...HEAD"
         else:
             # This assumes that the target branch of the pull request will be master.
-            merge_base = check_output(["git", "merge-base", "HEAD", "master"], universal_newlines=True, encoding="utf8").rstrip("\n")
+            merge_base = check_output(["git", "merge-base", "HEAD", "master"], text=True, encoding="utf8").rstrip("\n")
             commit_range = merge_base + "..HEAD"
     else:
         commit_range = os.getenv("COMMIT_RANGE")
         if commit_range == "SKIP_EMPTY_NOT_A_PR":
             sys.exit(0)
 
-    commit_hashes = check_output(["git", "log", commit_range, "--format=%H"], universal_newlines=True, encoding="utf8").splitlines()
+    commit_hashes = check_output(["git", "log", commit_range, "--format=%H"], text=True, encoding="utf8").splitlines()
 
     for hash in commit_hashes:
-        commit_info = check_output(["git", "log", "--format=%B", "-n", "1", hash], universal_newlines=True, encoding="utf8").splitlines()
+        commit_info = check_output(["git", "log", "--format=%B", "-n", "1", hash], text=True, encoding="utf8").splitlines()
         if len(commit_info) >= 2:
             if commit_info[1]:
                 print(f"The subject line of commit hash {hash} is followed by a non-empty line. Subject lines should always be followed by a blank line.")
diff --git a/test/lint/lint-includes.py b/test/lint/lint-includes.py
@@ -35,13 +35,13 @@
 
 
 def get_toplevel():
-    return check_output(["git", "rev-parse", "--show-toplevel"], universal_newlines=True, encoding="utf8").rstrip("\n")
+    return check_output(["git", "rev-parse", "--show-toplevel"], text=True, encoding="utf8").rstrip("\n")
 
 
 def list_files_by_suffix(suffixes):
     exclude_args = [":(exclude)" + dir for dir in EXCLUDED_DIRS]
 
-    files_list = check_output(["git", "ls-files", "src"] + exclude_args, universal_newlines=True, encoding="utf8").splitlines()
+    files_list = check_output(["git", "ls-files", "src"] + exclude_args, text=True, encoding="utf8").splitlines()
 
     return [file for file in files_list if file.endswith(suffixes)]
 
@@ -63,7 +63,7 @@ def find_included_cpps():
     included_cpps = list()
 
     try:
-        included_cpps = check_output(["git", "grep", "-E", r"^#include [<\"][^>\"]+\.cpp[>\"]", "--", "*.cpp", "*.h"], universal_newlines=True, encoding="utf8").splitlines()
+        included_cpps = check_output(["git", "grep", "-E", r"^#include [<\"][^>\"]+\.cpp[>\"]", "--", "*.cpp", "*.h"], text=True, encoding="utf8").splitlines()
     except CalledProcessError as e:
         if e.returncode > 1:
             raise e
@@ -77,7 +77,7 @@ def find_extra_boosts():
     exclusion_set = set()
 
     try:
-        included_boosts = check_output(["git", "grep", "-E", r"^#include <boost/", "--", "*.cpp", "*.h"], universal_newlines=True, encoding="utf8").splitlines()
+        included_boosts = check_output(["git", "grep", "-E", r"^#include <boost/", "--", "*.cpp", "*.h"], text=True, encoding="utf8").splitlines()
     except CalledProcessError as e:
         if e.returncode > 1:
             raise e
@@ -100,7 +100,7 @@ def find_quote_syntax_inclusions():
     quote_syntax_inclusions = list()
 
     try:
-        quote_syntax_inclusions = check_output(["git", "grep", r"^#include \"", "--", "*.cpp", "*.h"] + exclude_args, universal_newlines=True, encoding="utf8").splitlines()
+        quote_syntax_inclusions = check_output(["git", "grep", r"^#include \"", "--", "*.cpp", "*.h"] + exclude_args, text=True, encoding="utf8").splitlines()
     except CalledProcessError as e:
         if e.returncode > 1:
             raise e
@@ -143,13 +143,13 @@ def main():
     if extra_boosts:
         for boost in extra_boosts:
             print(f"A new Boost dependency in the form of \"{boost}\" appears to have been introduced:")
-            print(check_output(["git", "grep", boost, "--", "*.cpp", "*.h"], universal_newlines=True, encoding="utf8"))
+            print(check_output(["git", "grep", boost, "--", "*.cpp", "*.h"], text=True, encoding="utf8"))
         exit_code = 1
 
     # Check if Boost dependencies are no longer used
     for expected_boost in EXPECTED_BOOST_INCLUDES:
         try:
-            check_output(["git", "grep", "-q", r"^#include <%s>" % expected_boost, "--", "*.cpp", "*.h"], universal_newlines=True, encoding="utf8")
+            check_output(["git", "grep", "-q", r"^#include <%s>" % expected_boost, "--", "*.cpp", "*.h"], text=True, encoding="utf8")
         except CalledProcessError as e:
             if e.returncode > 1:
                 raise e
diff --git a/test/lint/lint-locale-dependence.py b/test/lint/lint-locale-dependence.py
diff --git a/test/lint/lint-logs.py b/test/lint/lint-logs.py
diff --git a/test/lint/lint-python-mutable-default-parameters.py b/test/lint/lint-python-mutable-default-parameters.py
diff --git a/test/lint/lint-python-utf8-encoding.py b/test/lint/lint-python-utf8-encoding.py
diff --git a/test/lint/lint-shell.py b/test/lint/lint-shell.py
diff --git a/test/lint/lint-submodule.py b/test/lint/lint-submodule.py
diff --git a/test/lint/lint-tests.py b/test/lint/lint-tests.py
diff --git a/test/lint/lint-whitespace.py b/test/lint/lint-whitespace.py
diff --git a/test/util/test_runner.py b/test/util/test_runner.py
