error opening trace file No such file or directory 2

Question

I am getting the above error       error opening trace file  No such file or directory  2    when I run my android application on the emulator   Can someone tell me what could be the possible reason for this   I am using android-sdk-20 and below lines are added to AndroidManifest xml   lt uses-sdk android minSdkVersion  14  android targetSdkVersion  15    gt    I have also added the line    lt uses-permission android name  android permission WRITE EXTERNAL STORAGE    gt    since I thought that there may be some issue with writing to the sd card

User · Answer

I didn t want to reinstall everything because I have so many SDK versions installed and my development environment is set up just right  Getting it set up again takes way too long   What worked for me was deleting  then re-creating the Android Virtual Device  being certain to put in a value for SD Card Size  I used 200 MiB      Additional information   while the above does fix the problem temporarily  it is recurring  I just tried my application within Android Studio and saw this in the output log which I did not notice before in Eclipse     Applications Android Studio app sdk tools emulator  -avd AVD for Nexus S by Google -netspeed full -netdelay none  WARNING  Data partition already in use  Changes will not persist  WARNING  SD Card image already in use   Users  user   android avd AVD for Nexus S by Google avd sdcard img ko Snapshot storage already in use   Users  user   android avd AVD for Nexus S by Google avd snapshots img   I suspect that changes to the log are not saving to the SD Card  so when LogCat tries to access the logs  they aren t there  causing the error message  The act of deleting the AVD and re-creating it removes the files  and the next launch is a fresh launch  allowing LogCat to access the virtual SD Card

User · Answer

Try removing the uses-sdk part form AndroidManifest xml file  it worked for me   Don t use the Android Virtual Device with too low configuration  Let it be medium

User · Answer

I think this is the problem  A little background  Traceview is a graphical viewer for execution logs that you create by using the Debug class to log tracing information in your code  Traceview can help you debug your application and profile its performance  Enabling it creates a  trace file in the sdcard root folder which can then be extracted by ADB and processed by traceview bat file for processing  It also can get added by the DDMS    It is a system used internally by the logger  In general unless you are using traceview to extract the trace file this error shouldnt bother you   You should look at error logs directly related to your application  How do I enable it      There are two ways to generate trace logs          Include the Debug class in your code and call its methods such as startMethodTracing   and stopMethodTracing    to start and stop   logging of trace information to disk  This option is very precise   because you can specify exactly where to start and stop logging trace   data in your code    Use the method profiling feature of DDMS to generate trace logs  This option is less precise because you do not modify code  but rather   specify when to start and stop logging with DDMS  Although you have   less control on exactly where logging starts and stops  this option is   useful if you don t have access to the application s code  or if you   do not need precise log timing       But the following restrictions exist for the above     If you are using the Debug class  your application must have   permission to write to external storage  WRITE EXTERNAL STORAGE         If you are using DDMS  Android 2 1 and earlier devices must have an SD   card present and your application must have permission to write to the   SD card  Android 2 2 and later devices do not need an SD card  The   trace log files are streamed directly to your development machine    So in essence the traceFile access requires two things     1   Permission to write a trace log file i e  WRITE EXTERNAL STORAGE and READ EXTERNAL STORAGE for good measure      2   An emulator with an SDCard attached with sufficient space  The doc doesnt say if this is only for DDMS but also for debug  so I am assuming this is also true for debugging via the application    What do I do with this error   Now the error is essentially a fall out of either not having the sdcard path to create a tracefile or not having permission to access it  This is an old thread  but the dev behind the bounty  check if are meeting the two prerequisites  You can then go search for the  trace file in the sdcard folder in your emulator  If it exists it shouldn t be giving you this problem  if it doesnt try creating it by adding the startMethodTracing to your app  I m not sure why it automatically looks for this file when the logger kicks in  I think when an error log event occurs   the logger internally tries to write to trace file and does not find it  in which case it throws the error Having scoured through the docs  I don t find too many references to why this is automatically on   But in general this doesn t affect you directly  you should check direct application logs errors   Also as an aside Android 2 2 and later devices do not need an SD card for DDMS trace logging  The trace log files are streamed directly to your development machine    Additional information on Traceview       Copying Trace Files to a Host Machine       After your application has run   and the system has created your trace files  trace on   a device or emulator  you must copy those files to your development   computer  You can use adb pull to copy the files  Here s an example   that shows how to copy an example file  calc trace  from the default   location on the emulator to the  tmp directory on the emulator host   machine       adb pull  sdcard calc trace  tmp Viewing Trace Files in Traceview To   run Traceview and view the trace files  enter traceview     For example  to run Traceview on the example files   copied in the previous section  use       traceview  tmp calc Note  If you are trying to view the trace logs of   an application that is built with ProGuard enabled  release mode   build   some method and member names might be obfuscated  You can use   the Proguard mapping txt file to figure out the original unobfuscated   names  For more information on this file  see the Proguard   documentation    I think any other answer regarding positioning of oncreate statements or removing uses-sdk are not related  but this is Android and I could be wrong  Would be useful to redirect this question to an android engineer or post it as a bug  More in the docs

User · Answer

Write all your code below this 2 lines -      super onCreate savedInstanceState       setContentView R layout activity main     It worked for me without re-installing again

User · Answer

It happens because you have not installed the minSdkVersion or targetSdkVersion in you   re computer  I ve tested it right now   For example  if you have those lines in your Manifest xml    lt uses-sdk android minSdkVersion  8  android targetSdkVersion  17    gt    And you have installed only the API17 in your computer  it will report you an error  If you want to test it  try installing the other API version  in this case  API 8    Even so  it s not an important error  It doesn t mean that your app is wrong   Sorry about my expression  English is not my language  Bye

User · Answer

Actually  the problem is that either  sys kernel debug is not mounted  or that the running kernel has no ftrace tracers compiled in so that  sys kernel debug tracing is unavailable  This is the code throwing the error  platform frameworks native libs utils Trace cpp    void Tracer  init         Mutex  Autolock lock sMutex        if   sIsReady            add sysprop change callback changeCallback  0            const char  const traceFileName                     sys kernel debug tracing trace marker           sTraceFD   open traceFileName  O WRONLY           if  sTraceFD    -1                ALOGE  error opening trace file   s   d    strerror errno   errno               sEnabledTags   0       no tracing can occur           else               loadSystemProperty                       android atomic release store 1   amp sIsReady             The log message could definitely be a bit more informative

User · Answer

You will not have access to your real sd card in emulator  You will have to follow the steps in this tutorial to direct your emulator to a directory on your development environment acting as your SD card

[android] error opening trace file: No such file or directory (2)

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