I want to capture a system trace, using the systrace tool.

I have this device (not-rooted) : Pixi 4.5 Alcatel Android 6.0 (API 23)

And I use Android Studio 4.2.2 and I have installed Python 2.7.18, as required (the version 3+ does not match).

Here is the command line to view the list of available categories on my device :

C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace>C:\Users\myUser\AppData\Local\Programs\Python27\python systrace.py -l

I chose this command with the -l option for my here question because it results (see below) in the expected list plus an extra set of lines which suggests that the error CommandFailedError is related to an exception on HasRoot :

       gfx - Graphics

       input - Input

        view - View System

     webview - WebView

          wm - Window Manager

          am - Activity Manager

          sm - Sync Manager

       audio - Audio

       video - Video

      camera - Camera

         hal - Hardware Modules

         app - Application

         res - Resource Loading

      dalvik - Dalvik VM

          rs - RenderScript

        hwui - HWUI

        perf - Performance

      bionic - Bionic C Library

       power - Power Management

       sched - CPU Scheduling

        freq - CPU Frequency

        idle - CPU Idle

        load - CPU Load

CRITICAL:root:(TimeoutThread-1-for-MainThread) Exception on HasRoot(myDeviceId, retries=3, timeout=30), attempt 1 of 4: CommandFailedError("(device: myDeviceId) one line of output was expected, but got: ['uid=2000(shell) gid=2000(shell) groups=2000(shell),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcar
d_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats) context=u:r:shell:s0', '']",)
CRITICAL:root:(TimeoutThread-2-for-MainThread) Exception on HasRoot(myDeviceId, retries=3, timeout=30), attempt 2 of 4: CommandFailedError("(device: myDeviceId) one line of output was expected, but got: ['uid=2000(shell) gid=2000(shell) groups=2000(shell),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcar
d_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats) context=u:r:shell:s0', '']",)
CRITICAL:root:(TimeoutThread-3-for-MainThread) Exception on HasRoot(myDeviceId, retries=3, timeout=30), attempt 3 of 4: CommandFailedError("(device: myDeviceId) one line of output was expected, but got: ['uid=2000(shell) gid=2000(shell) groups=2000(shell),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcar
d_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats) context=u:r:shell:s0', '']",)
Traceback (most recent call last):
  File "systrace.py", line 49, in <module>
    sys.exit(run_systrace.main())
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\run_systrace.py", line 205, in main
    main_impl(sys.argv)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\run_systrace.py", line 177, in main_impl
    atrace_agent.list_categories(options)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\tracing_agents\atrace_agent.py", line 65, in list_categories
    if not devutils.HasRoot():
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 63, in timeout_r
etry_wrapper
    impl, timeout, retries, desc=desc, retry_if_func=retry_if_func)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\timeout_retry.py", line 164, in Run
    error_log_func=error_log_func)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\reraiser_thread.py", line 199, in JoinA
ll
    self._JoinAll(watcher, timeout)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\reraiser_thread.py", line 171, in _Join
All
    thread.ReraiseIfException()
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\reraiser_thread.py", line 94, in run
    self._ret = self._func(*self._args, **self._kwargs)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\timeout_retry.py", line 156, in <lambda
>
    lambda: func(*args, **kwargs), name=thread_name)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 51, in impl
    return f(*args, **kwargs)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\device_utils.py", line 562, in HasRoo
t
    output = self.RunShellCommand(['id'], single_line=True)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 56, in timeout_r
etry_wrapper
    return impl()
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 51, in impl
    return f(*args, **kwargs)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\device_utils.py", line 1556, in RunSh
ellCommand
    raise device_errors.CommandFailedError(msg % output, str(self))
devil.android.device_errors.CommandFailedError: (device: myDeviceId) one line of output was expected, but got: ['uid=2000(shell) gid=2000(shell) groups=2000(
shell),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats) context=u:r:shell:s0', '']

By comparison, here is the error CommandFailedError obtained with a command which should generate an html report :

C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace>C:\Users\myUser\AppData\Local\Programs\Python27\python systrace.py

Traceback (most recent call last):
  File "systrace.py", line 49, in <module>
    sys.exit(run_systrace.main())
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\run_systrace.py", line 205, in main
    main_impl(sys.argv)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\run_systrace.py", line 185, in main_impl
    controller.StartTracing()
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\systrace_runner.py", line 46, in StartTracing
    self._tracing_controller.StartTracing()
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\tracing_controller.py", line 156, in StartTracing
    timeout=self._controller_config.timeout):
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\common\py_utils\py_utils\__init__.py", line 103, in RunWithTimeout
    return timeout_retry.Run(func, timeout, 0, args=args)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\timeout_retry.py", line 164, in Run
    error_log_func=error_log_func)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\reraiser_thread.py", line 199, in JoinA
ll
    self._JoinAll(watcher, timeout)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\reraiser_thread.py", line 171, in _Join
All
    thread.ReraiseIfException()
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\reraiser_thread.py", line 94, in run
    self._ret = self._func(*self._args, **self._kwargs)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\utils\timeout_retry.py", line 156, in <lambda
>
    lambda: func(*args, **kwargs), name=thread_name)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\tracing_agents\android_cgroup_agent.py", line 59, in StartAgent
Tracing
    if not self._device_utils.HasRoot():
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 56, in timeout_r
etry_wrapper
    return impl()
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 51, in impl
    return f(*args, **kwargs)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\device_utils.py", line 562, in HasRoo
t
    output = self.RunShellCommand(['id'], single_line=True)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 56, in timeout_r
etry_wrapper
    return impl()
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\decorators.py", line 51, in impl
    return f(*args, **kwargs)
  File "C:\Users\myUser\AppData\Local\Android\Sdk\platform-tools\systrace\catapult\systrace\systrace\..\..\devil\devil\android\device_utils.py", line 1556, in RunSh
ellCommand
    raise device_errors.CommandFailedError(msg % output, str(self))
devil.android.device_errors.CommandFailedError: (device: deviceId) one line of output was expected, but got: ['uid=2000(shell) gid=2000(shell) groups=2000(
shell),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats) context=u:r:shell:s0', '']

I am sure that there is a proper way to run systrace on an old unrooted device but I just didn't find it.

Does anyone have a clue or a solution? Thanks.

EDIT :

Thanks a lot for your analysis and your answer @yi-yang.

As you recommended, I set single_line to False in the RunShellCommand call. Furthermore, I also modified the return line, which gives the final code in the device_utils.py file, lines 562-563 :

output = self.RunShellCommand(['id'], single_line=False)
return output[0].startswith('uid=0(root)')

Note that I select the first line because there are still two lines, which means that some optional newline at the end needs to be stripped somehow...

Now it works but only for a few categories, as in the following example:

systrace.py -o mynewtrace.html perf idle load

However, for any atrace data, including the very helpful "sched" (see atrace_agent.py), the cpu profiling not possible, as shown by the following messages:

Warning: Only 2 of 3 tracing agents started.
IOError('Unable to get atrace data. Did you forget adb root?')

So the root privileges do matter, despite what the file comments (l. 556-558) claim :-(. I guess rooting is a must for the full experience!