Feb 3, 2026 · Feb 3, 2026 · Feb 3, 2026
diff --git a/Android/android.py b/Android/android.py
 from asyncio import wait_for
 from contextlib import asynccontextmanager
 from datetime import datetime, timezone
 from enum import IntEnum, auto
 from glob import glob
 from os.path import abspath, basename, relpath
 from pathlib import Path
 hidden_output = []


 # Based on android/log.h in the NDK.
 class LogPriority(IntEnum):
    UNKNOWN = 0
    DEFAULT = auto()
    VERBOSE = auto()
    DEBUG = auto()
    INFO = auto()
    WARN = auto()
    ERROR = auto()
    FATAL = auto()
    SILENT = auto()


 def log_verbose(context, line, stream=sys.stdout):
    if context.verbose:
        stream.write(line)
    pid = await wait_for(find_pid(serial), startup_timeout)

    # `--pid` requires API level 24 or higher.
    args = [adb, "-s", serial, "logcat", "--pid", pid,  "--format", "tag"]
    #
    # `--binary` mode is used in order to detect which messages end with a
    # newline, which most of the other modes don't indicate (except `--format
    # long`). For example, every time pytest runs a test, it prints a "." and
    # flushes the stream. Each "." becomes a separate log message, but we should
    # show them all on the same line.
    args = [adb, "-s", serial, "logcat", "--pid", pid,  "--binary"]
    logcat_started = False
    async with async_process(
        *args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
        *args, stdout=subprocess.PIPE, stderr=None
    ) as process:
        while line := (await process.stdout.readline()).decode(*DECODE_ARGS):
            if match := re.fullmatch(r"([A-Z])/(.*)", line, re.DOTALL):
        while True:
            try:
                priority, tag, message = await read_logcat(process.stdout)
                logcat_started = True
                level, message = match.groups()
            else:
                # If the regex doesn't match, this is either a logcat startup
                # error, or the second or subsequent line of a multi-line
                # message. Python won't produce multi-line messages, but other
                # components might.
                level, message = None, line
            except asyncio.IncompleteReadError:
                break

            # Exclude high-volume messages which are rarely useful.
            if context.verbose < 2 and "from python test_syslog" in message:
                continue

            # Put high-level messages on stderr so they're highlighted in the
            # buildbot logs. This will include Python's own stderr.
            stream = (
                sys.stderr
                if level in ["W", "E", "F"]  # WARNING, ERROR, FATAL (aka ASSERT)
                else sys.stdout
            )

            # To simplify automated processing of the output, e.g. a buildbot
            # posting a failure notice on a GitHub PR, we strip the level and
            # tag indicators from Python's stdout and stderr.
            for prefix in ["python.stdout: ", "python.stderr: "]:
                if message.startswith(prefix):
                    global python_started
                    python_started = True
                    stream.write(message.removeprefix(prefix))
                    break
            stream = sys.stderr if priority >= LogPriority.WARN else sys.stdout

            # The app's stdout and stderr should be passed through transparently
            # to our own corresponding streams.
            if tag in ["python.stdout", "python.stderr"]:
                global python_started
                python_started = True
                stream.write(message)
                stream.flush()
            else:
                # Non-Python messages add a lot of noise, but they may
                # sometimes help explain a failure.
                log_verbose(context, line, stream)
                # sometimes help explain a failure. Format them in the same way
                # as `logcat --format tag`.
                formatted = f"{priority.name[0]}/{tag}: {message}"
                if not formatted.endswith("\n"):
                    formatted += "\n"
                log_verbose(context, formatted, stream)

        # If the device disconnects while logcat is running, which always
        # happens in --managed mode, some versions of adb return non-zero.
            raise CalledProcessError(status, args)


 # Read one binary log message from the given StreamReader. The message format is
 # described at https://android.stackexchange.com/a/74660. All supported versions
 # of Android use format version 2 or later.
 async def read_logcat(stream):
    async def read_bytes(size):
        return await stream.readexactly(size)

    async def read_int(size):
        return int.from_bytes(await read_bytes(size), "little")

    payload_len = await read_int(2)
    if payload_len < 2:
        # 1 byte for priority, 1 byte for null terminator of tag.
        raise ValueError(f"payload length {payload_len} is too short")

    header_len = await read_int(2)
    if header_len < 4:
        raise ValueError(f"header length {header_len} is too short")
    await read_bytes(header_len - 4)  # Ignore other header fields.

    priority_int = await read_int(1)
    try:
        priority = LogPriority(priority_int)
    except ValueError:
        priority = LogPriority.UNKNOWN

    payload_fields = (await read_bytes(payload_len - 1)).split(b"\0")
    if len(payload_fields) < 2:
        raise ValueError(
            f"payload {payload!r} does not contain at least 2 "
            f"null-separated fields"
        )
    tag, message, *_ = [
        field.decode(*DECODE_ARGS) for field in payload_fields
    ]
    return priority, tag, message


 def stop_app(serial):
    run([adb, "-s", serial, "shell", "am", "force-stop", APP_ID], log=False)

diff --git a/Android/testbed/app/build.gradle.kts b/Android/testbed/app/build.gradle.kts
        }

        // This controls the API level of the maxVersion managed emulator, which is used
        // by CI and cibuildwheel. 34 takes up too much disk space (#142289), 35 has
        // issues connecting to the internet (#142387), and 36 and later are not
        // available as aosp_atd images yet.
        targetSdk = 33
        // by CI and cibuildwheel.
        //  * 33 has excessive buffering in the logcat client
        //    (https://cs.android.com/android/_/android/platform/system/logging/+/d340721894f223327339010df59b0ac514308826).
        //  * 34 consumes too much disk space on GitHub Actions (#142289).
        //  * 35 has issues connecting to the internet (#142387).
        //  * 36 and later are not available as aosp_atd images yet.
        targetSdk = 32

        versionCode = 1
        versionName = "1.0"
        path("src/main/c/CMakeLists.txt")
    }

    // Set this property to something non-empty, otherwise it'll use the default
    // list, which ignores asset directories beginning with an underscore.
    aaptOptions.ignoreAssetsPattern = ".git"
    // Set this property to something nonexistent but non-empty. Otherwise it'll use the
    // default list, which ignores asset directories beginning with an underscore, and
    // maybe also other files required by tests.
    aaptOptions.ignoreAssetsPattern = "android-testbed-dont-ignore-anything"

    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
                    from(cwd)
                }
            }

            // A filename ending with .gz will be automatically decompressed
            // while building the APK. Avoid this by adding a dash to the end,
            // and add an extra dash to any filenames that already end with one.
            // This will be undone in MainActivity.kt.
            rename(""".*(\.gz|-)""", "$0-")
        }
    }

diff --git a/Android/testbed/app/src/main/java/org/python/testbed/MainActivity.kt b/Android/testbed/app/src/main/java/org/python/testbed/MainActivity.kt
 continue
            }
            input.use {
 File(targetSubdir, name).outputStream().use { output->
 // Undo the .gz workaround from build.gradle.kts.
 val outputName= name.replace(Regex("""(.*)-"""),"$1")
 File(targetSubdir, outputName).outputStream().use { output->
                    input.copyTo(output)
                }
            }
diff --git a/Lib/_android_support.py b/Lib/_android_support.py
 # message.
 message=message.replace(b"\x00",b"\xc0\x80")

 # On API level 30 and higher, Logcat will strip any number of leading
 # newlines. This is visible in all `logcat` modes, even --binary. Work
 # around this by adding a leading space, which shouldn't make any
 # difference to the log's usability.
 ifmessage.startswith(b"\n"):
 message=b" "+message

 withself._lock:
 now=time()
 self._bucket_level+= (
diff --git a/Lib/test/test_android.py b/Lib/test/test_android.py

                # Multi-line messages. Avoid identical consecutive lines, as
                # they may activate "chatty" filtering and break the tests.
                write("\nx", [""])
                #
                # Additional spaces will appear in the output where necessary to
                # protect leading newlines.
                write("\nx", [" "])
                write("\na\n", ["x", "a"])
                write("\n", [""])
                write("\n", [" "])
                write("\n\n", [" ", " "])
                write("b\n", ["b"])
                write("c\n\n", ["c", ""])
                write("c\n\n", ["c", ""])
                write("d\ne", ["d"])
                write("xx", [])
                write("f\n\ng", ["exxf", ""])
                write("f\n\ng", ["exxf", ""])
                write("\n", ["g"])

                # Since this is a line-based logging system, line buffering
                # However, buffering can be turned off completely if you want a
                # flush after every write.
                with self.reconfigure(stream, write_through=True):
                    write("\nx", ["", "x"])
                    write("\na\n", ["", "a"])
                    write("\n", [""])
                    write("\nx", [" ", "x"])
                    write("\na\n", [" ", "a"])
                    write("\n", [" "])
                    write("\n\n", [" ", " "])
                    write("b\n", ["b"])
                    write("c\n\n", ["c", ""])
                    write("c\n\n", ["c", ""])
                    write("d\ne", ["d", "e"])
                    write("xx", ["xx"])
                    write("f\n\ng", ["f", "", "g"])
                    write("\n", [""])
                    write("f\n\ng", ["f", "", "g"])
                    write("\n", [""])

                # "\r\n" should be translated into "\n".
                write("hello\r\n", ["hello"])
                # currently use `logcat -v tag`, which shows each line as if it
                # was a separate log entry, but strips a single trailing
                # newline.
                #
                # On newer versions of Android, all three of the above tools (or
                # maybe Logcat itself) will also strip any number of leading
                # newlines.
                write(b"\nx", ["", "x"] if api_level < 30 else ["x"])
                write(b"\na\n", ["", "a"] if api_level < 30 else ["a"])
                write(b"\n", [""])
                write(b"\nx", [" ", "x"])
                write(b"\na\n", [" ", "a"])
                write(b"\n", [" "])
                write(b"\n\n", [" ", ""])
                write(b"b\n", ["b"])
                write(b"c\n\n", ["c", ""])
                write(b"d\ne", ["d", "e"])
                write(b"xx", ["xx"])
                write(b"f\n\ng", ["f", "", "g"])
                write(b"\n", [""])
                write(b"\n", [""])

                # "\r\n" should be translated into "\n".
                write(b"hello\r\n", ["hello"])
diff --git a/Misc/NEWS.d/next/Tests/2026-02-03-07-57-24.gh-issue-144415.U3L15r.rst b/Misc/NEWS.d/next/Tests/2026-02-03-07-57-24.gh-issue-144415.U3L15r.rst
 The Android testbed now distinguishes between stdout/stderr messages which
 were triggered by a newline, and those triggered by a manual call to
 ``flush``. This fixes logging of progress indicators and similar content.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -15,6 +15,7 @@
		from asyncio import wait_for
		from contextlib import asynccontextmanager
		from datetime import datetime, timezone
		from enum import IntEnum, auto
		from glob import glob
		from os.path import abspath, basename, relpath
		from pathlib import Path
Expand DownExpand Up		@@ -61,6 +62,19 @@
		hidden_output = []


		# Based on android/log.h in the NDK.
		class LogPriority(IntEnum):
		UNKNOWN = 0
		DEFAULT = auto()
		VERBOSE = auto()
		DEBUG = auto()
		INFO = auto()
		WARN = auto()
		ERROR = auto()
		FATAL = auto()
		SILENT = auto()


		def log_verbose(context, line, stream=sys.stdout):
		if context.verbose:
		stream.write(line)
Expand DownExpand Up		@@ -505,47 +519,47 @@ async def logcat_task(context, initial_devices):
		pid = await wait_for(find_pid(serial), startup_timeout)

		# `--pid` requires API level 24 or higher.
		args = [adb, "-s", serial, "logcat", "--pid", pid, "--format", "tag"]
		#
		# `--binary` mode is used in order to detect which messages end with a
		# newline, which most of the other modes don't indicate (except `--format
		# long`). For example, every time pytest runs a test, it prints a "." and
		# flushes the stream. Each "." becomes a separate log message, but we should
		# show them all on the same line.
		args = [adb, "-s", serial, "logcat", "--pid", pid, "--binary"]
		logcat_started = False
		async with async_process(
		*args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
		*args, stdout=subprocess.PIPE, stderr=None
		) as process:
		while line := (await process.stdout.readline()).decode(*DECODE_ARGS):
		if match := re.fullmatch(r"([A-Z])/(.*)", line, re.DOTALL):
		while True:
		try:
		priority, tag, message = await read_logcat(process.stdout)
		logcat_started = True
		level, message = match.groups()
		else:
		# If the regex doesn't match, this is either a logcat startup
		# error, or the second or subsequent line of a multi-line
		# message. Python won't produce multi-line messages, but other
		# components might.
		level, message = None, line
		except asyncio.IncompleteReadError:
		break

		# Exclude high-volume messages which are rarely useful.
		if context.verbose < 2 and "from python test_syslog" in message:
		continue

		# Put high-level messages on stderr so they're highlighted in the
		# buildbot logs. This will include Python's own stderr.
		stream = (
		sys.stderr
		if level in ["W", "E", "F"] # WARNING, ERROR, FATAL (aka ASSERT)
		else sys.stdout
		)

		# To simplify automated processing of the output, e.g. a buildbot
		# posting a failure notice on a GitHub PR, we strip the level and
		# tag indicators from Python's stdout and stderr.
		for prefix in ["python.stdout: ", "python.stderr: "]:
		if message.startswith(prefix):
		global python_started
		python_started = True
		stream.write(message.removeprefix(prefix))
		break
		stream = sys.stderr if priority >= LogPriority.WARN else sys.stdout

		# The app's stdout and stderr should be passed through transparently
		# to our own corresponding streams.
		if tag in ["python.stdout", "python.stderr"]:
		global python_started
		python_started = True
		stream.write(message)
		stream.flush()
		else:
		# Non-Python messages add a lot of noise, but they may
		# sometimes help explain a failure.
		log_verbose(context, line, stream)
		# sometimes help explain a failure. Format them in the same way
		# as `logcat --format tag`.
		formatted = f"{priority.name[0]}/{tag}: {message}"
		if not formatted.endswith("\n"):
		formatted += "\n"
		log_verbose(context, formatted, stream)

		# If the device disconnects while logcat is running, which always
		# happens in --managed mode, some versions of adb return non-zero.
Expand All		@@ -556,6 +570,44 @@ async def logcat_task(context, initial_devices):
		raise CalledProcessError(status, args)


		# Read one binary log message from the given StreamReader. The message format is
		# described at https://android.stackexchange.com/a/74660. All supported versions
		# of Android use format version 2 or later.
		async def read_logcat(stream):
		async def read_bytes(size):
		return await stream.readexactly(size)

		async def read_int(size):
		return int.from_bytes(await read_bytes(size), "little")

		payload_len = await read_int(2)
		if payload_len < 2:
		# 1 byte for priority, 1 byte for null terminator of tag.
		raise ValueError(f"payload length {payload_len} is too short")

		header_len = await read_int(2)
		if header_len < 4:
		raise ValueError(f"header length {header_len} is too short")
		await read_bytes(header_len - 4) # Ignore other header fields.

		priority_int = await read_int(1)
		try:
		priority = LogPriority(priority_int)
		except ValueError:
		priority = LogPriority.UNKNOWN

		payload_fields = (await read_bytes(payload_len - 1)).split(b"\0")
		if len(payload_fields) < 2:
		raise ValueError(
		f"payload {payload!r} does not contain at least 2 "
		f"null-separated fields"
		)
		tag, message, *_ = [
		field.decode(*DECODE_ARGS) for field in payload_fields
		]
		return priority, tag, message


		def stop_app(serial):
		run([adb, "-s", serial, "shell", "am", "force-stop", APP_ID], log=False)

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -94,10 +94,13 @@ android {
		}

		// This controls the API level of the maxVersion managed emulator, which is used
		// by CI and cibuildwheel. 34 takes up too much disk space (#142289), 35 has
		// issues connecting to the internet (#142387), and 36 and later are not
		// available as aosp_atd images yet.
		targetSdk = 33
		// by CI and cibuildwheel.
		// * 33 has excessive buffering in the logcat client
		// (https://cs.android.com/android/_/android/platform/system/logging/+/d340721894f223327339010df59b0ac514308826).
		// * 34 consumes too much disk space on GitHub Actions (#142289).
		// * 35 has issues connecting to the internet (#142387).
		// * 36 and later are not available as aosp_atd images yet.
		targetSdk = 32

		versionCode = 1
		versionName = "1.0"
Expand DownExpand Up		@@ -130,9 +133,10 @@ android {
		path("src/main/c/CMakeLists.txt")
		}

		// Set this property to something non-empty, otherwise it'll use the default
		// list, which ignores asset directories beginning with an underscore.
		aaptOptions.ignoreAssetsPattern = ".git"
		// Set this property to something nonexistent but non-empty. Otherwise it'll use the
		// default list, which ignores asset directories beginning with an underscore, and
		// maybe also other files required by tests.
		aaptOptions.ignoreAssetsPattern = "android-testbed-dont-ignore-anything"

		compileOptions {
		sourceCompatibility = JavaVersion.VERSION_1_8
Expand DownExpand Up		@@ -234,6 +238,12 @@ androidComponents.onVariants { variant ->
		from(cwd)
		}
		}

		// A filename ending with .gz will be automatically decompressed
		// while building the APK. Avoid this by adding a dash to the end,
		// and add an extra dash to any filenames that already end with one.
		// This will be undone in MainActivity.kt.
		rename(""".*(\.gz\|-)""", "$0-")
		}
		}

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -80,7 +80,9 @@ class PythonTestRunner(val context: Context) {
		continue
		}
		input.use {
		File(targetSubdir, name).outputStream().use { output->
		// Undo the .gz workaround from build.gradle.kts.
		val outputName= name.replace(Regex("""(.*)-"""),"$1")
		File(targetSubdir, outputName).outputStream().use { output->
		input.copyTo(output)
		}
		}
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -168,6 +168,13 @@ def write(self, prio, tag, message):
		# message.
		message=message.replace(b"\x00",b"\xc0\x80")

		# On API level 30 and higher, Logcat will strip any number of leading
		# newlines. This is visible in all `logcat` modes, even --binary. Work
		# around this by adding a leading space, which shouldn't make any
		# difference to the log's usability.
		ifmessage.startswith(b"\n"):
		message=b" "+message

		withself._lock:
		now=time()
		self._bucket_level+= (
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -183,14 +183,18 @@ def write(s, lines=None, *, write_len=None):

		# Multi-line messages. Avoid identical consecutive lines, as
		# they may activate "chatty" filtering and break the tests.
		write("\nx", [""])
		#
		# Additional spaces will appear in the output where necessary to
		# protect leading newlines.
		write("\nx", [" "])
		write("\na\n", ["x", "a"])
		write("\n", [""])
		write("\n", [" "])
		write("\n\n", [" ", " "])
		write("b\n", ["b"])
		write("c\n\n", ["c", ""])
		write("c\n\n", ["c", ""])
		write("d\ne", ["d"])
		write("xx", [])
		write("f\n\ng", ["exxf", ""])
		write("f\n\ng", ["exxf", ""])
		write("\n", ["g"])

		# Since this is a line-based logging system, line buffering
Expand All		@@ -201,15 +205,16 @@ def write(s, lines=None, *, write_len=None):
		# However, buffering can be turned off completely if you want a
		# flush after every write.
		with self.reconfigure(stream, write_through=True):
		write("\nx", ["", "x"])
		write("\na\n", ["", "a"])
		write("\n", [""])
		write("\nx", [" ", "x"])
		write("\na\n", [" ", "a"])
		write("\n", [" "])
		write("\n\n", [" ", " "])
		write("b\n", ["b"])
		write("c\n\n", ["c", ""])
		write("c\n\n", ["c", ""])
		write("d\ne", ["d", "e"])
		write("xx", ["xx"])
		write("f\n\ng", ["f", "", "g"])
		write("\n", [""])
		write("f\n\ng", ["f", "", "g"])
		write("\n", [""])

		# "\r\n" should be translated into "\n".
		write("hello\r\n", ["hello"])
Expand DownExpand Up		@@ -329,19 +334,16 @@ def write(b, lines=None, *, write_len=None):
		# currently use `logcat -v tag`, which shows each line as if it
		# was a separate log entry, but strips a single trailing
		# newline.
		#
		# On newer versions of Android, all three of the above tools (or
		# maybe Logcat itself) will also strip any number of leading
		# newlines.
		write(b"\nx", ["", "x"] if api_level < 30 else ["x"])
		write(b"\na\n", ["", "a"] if api_level < 30 else ["a"])
		write(b"\n", [""])
		write(b"\nx", [" ", "x"])
		write(b"\na\n", [" ", "a"])
		write(b"\n", [" "])
		write(b"\n\n", [" ", ""])
		write(b"b\n", ["b"])
		write(b"c\n\n", ["c", ""])
		write(b"d\ne", ["d", "e"])
		write(b"xx", ["xx"])
		write(b"f\n\ng", ["f", "", "g"])
		write(b"\n", [""])
		write(b"\n", [""])

		# "\r\n" should be translated into "\n".
		write(b"hello\r\n", ["hello"])
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		The Android testbed now distinguishes between stdout/stderr messages which
		were triggered by a newline, and those triggered by a manual call to
		``flush``. This fixes logging of progress indicators and similar content.