Hide strange unwanted Xcode logs

Try this:

1 - From Xcode menu open: Product > Scheme > Edit Scheme

2 - On your Environment Variables set OS_ACTIVITY_MODE = disable

https://i.stack.imgur.com/p7BlV.png

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Building on the original tweet from @rustyshelf, and illustrated answer from iDevzilla, here's a solution that silences the noise from the simulator without disabling NSLog output from the device.

Under Product > Scheme > Edit Scheme... > Run (Debug), set the OS_ACTIVITY_MODE environment variable to ${DEBUG_ACTIVITY_MODE} so it looks like this:

https://i.stack.imgur.com/TpUsV.png

Go to your project build settings, and click + to add a User-Defined Setting named DEBUG_ACTIVITY_MODE. Expand this setting and Click the + next to Debug to add a platform-specific value. Select the dropdown and change it to "Any iOS Simulator". Then set its value to "disable" so it looks like this:

https://i.stack.imgur.com/9Eumr.png

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OS_ACTIVITY_MODE didn't work for me (it may have been because I typo'd disable as disabled, but isn't that more natural?!?), or at least didn't prevent a great deal of messages. So here's the real deal with the environment variables.

https://llvm.org/svn/llvm-project/lldb/trunk/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp

lldb_private::Error
PlatformDarwin::LaunchProcess(lldb_private::ProcessLaunchInfo &launch_info) {
  // Starting in Fall 2016 OSes, NSLog messages only get mirrored to stderr
  // if the OS_ACTIVITY_DT_MODE environment variable is set.  (It doesn't
  // require any specific value; rather, it just needs to exist).
  // We will set it here as long as the IDE_DISABLED_OS_ACTIVITY_DT_MODE flag
  // is not set.  Xcode makes use of IDE_DISABLED_OS_ACTIVITY_DT_MODE to tell
  // LLDB *not* to muck with the OS_ACTIVITY_DT_MODE flag when they
  // specifically want it unset.
  const char *disable_env_var = "IDE_DISABLED_OS_ACTIVITY_DT_MODE";
  auto &env_vars = launch_info.GetEnvironmentEntries();
  if (!env_vars.ContainsEnvironmentVariable(disable_env_var)) {
    // We want to make sure that OS_ACTIVITY_DT_MODE is set so that
    // we get os_log and NSLog messages mirrored to the target process
    // stderr.
    if (!env_vars.ContainsEnvironmentVariable("OS_ACTIVITY_DT_MODE"))
      env_vars.AppendArgument(llvm::StringRef("OS_ACTIVITY_DT_MODE=enable"));
  }

  // Let our parent class do the real launching.
  return PlatformPOSIX::LaunchProcess(launch_info);
}

So setting OS_ACTIVITY_DT_MODE to "NO" in the environment variables (GUI method explained in Schemes screenshot in main answer) makes it work for me.

As far as NSLog being the dumping ground for system messages, errors, and your own debugging: a real logging approach is probably called for anyway, e.g. https://github.com/fpillet/NSLogger .

OR

Drink the new Kool-Aid: http://asciiwwdc.com/2016/sessions/721 https://developer.apple.com/videos/play/wwdc2016/721/ It's not surprising that there are some hitches after overhauling the entire logging API.

ADDENDUM

Anyway, NSLog is just a shim:

https://developer.apple.com/library/content/releasenotes/Miscellaneous/RN-Foundation-OSX10.12/

NSLog / CFLog NSLog is now just a shim to os_log in most circumstances.

Only makes sense now to quote the source for the other env variable. Quite a disparate place, this time from Apple internals. Not sure why they are overlapping. [Incorrect comment about NSLog removed]

[Edited 22 Sep]: I wonder what "release" and "stream" do differently than "debug". Not enough source.

https://github.com/macosforge/libdispatch/blob/8e63547ea4e5abbfe55c0c3064181c4950a791d3/src/voucher.c

e = getenv("OS_ACTIVITY_MODE");
if (e) {
    if (strcmp(e, "release") == 0) {
        mode = voucher_activity_mode_release;
    } else if (strcmp(e, "debug") == 0) {
        mode = voucher_activity_mode_debug;
    } else if (strcmp(e, "stream") == 0) {
        mode = voucher_activity_mode_stream;
    } else if (strcmp(e, "disable") == 0) {
        mode = voucher_activity_mode_disable;
    }
}

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A tweet had the answer for me - https://twitter.com/rustyshelf/status/775505191160328194

To stop the Xcode 8 iOS Simulator from logging like crazy, set an environment variable OS_ACTIVITY_MODE = disable in your debug scheme.

It worked.

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Please find the below steps.

Select Product => Scheme => Edit Scheme or use shortcut : CMD + < Select the Run option from left side. On Environment Variables section, add the variable OS_ACTIVITY_MODE = disable

For more information please find the below GIF representation.

https://i.stack.imgur.com/vv2R8.gif

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This is still not fixed in Xcode Version 8.0 beta 2 (8S162m) for me and extra logs are also appearing in the Xcode console

** EDIT 8/1/16: This has been acknowledged in the release notes for Xcode 8 Beta 4 (8S188o) as an issues still persisting.

Known Issues in Xcode 8 beta 4 – IDE Debugging • Xcode Debug Console shows extra logging from system frameworks when debugging applications in the Simulator. (27331147, 26652255)

Presumably this will be resolved by the GM release. Until then patience and although not ideal but a workaround I'm using is below...

Similar to the previous answer I am having to:

prefix my print logs with some kind of special character (eg * or ^ or ! etc etc)

Then use the search box on the bottom right of the console pane to filter my console logs by inputing my chosen special character to get the console to display my print logs as intended

https://i.stack.imgur.com/UvIry.png

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My solution is to use the debugger command and/or Log Message in breakpoints.

https://i.stack.imgur.com/Je9HQ.png

And change the output of console from All Output to Debugger Output like

https://i.stack.imgur.com/IAxru.png

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Alright. There seems to be a lot of commotion about this one, so I'll give y'all a way to persist it without using that scheme trick. I'll address the iOS Simulator specifically, but this also might need to be applied for the TV Sim as well which is located in a different dir.

The problem that is causing all of this stuff are plists located within the Xcode directory. There is a process that gets launched called configd_sim when the Sim starts that reads the plists in and prints debugging information if the plists specify they should be logged.

The plists are located here:

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/System/Library/Preferences/Logging/Subsystems

If you are playing around with a beta, take note that the dir will be different.

You will see numerous plists in this directory. Now, build and run your application and observe the logs. You are looking for the content immediately followed by the subsystem: part. It is the name immediately following this that represents the corresponding problematic plist.

https://i.stack.imgur.com/QcyAt.png

From there, either modify the plist to knock out the debugging [Level] key/value which is a dictionary containing the "Enable" => "Default" key/value... or just simply delete the plist. Note, that you will need to be root to do either of these since they're located in the Xcode application.

the plutil -p command might be of use to you as well. i.e.

plutil -p /Applications/Xcode.app/Contents/Developer/Platforms/AppleTVSimulator.platform/Developer/SDKs/AppleTVSimulator.sdk/System/Library/Preferences/Logging/Subsystems/com.apple.BackBoardServices.fence.plist

This gave me one of the problematic plists which contained:

{ "DEFAULT-OPTIONS" => { "Level" => { "Enable" => "Default" }}}

Good luck :]

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This is related to a known issue with logging found in the Xcode 8 Beta Release Notes (also asked an engineer at WWDC).

When debugging WatchOS applications in the Watch simulator, the OS may produce an excessive amount of unhelpful logging. (26652255)

There is currently no workaround available, you must wait for a new version of Xcode.

EDIT 7/5/16: This is supposedly fixed as of Xcode 8 Beta 2:

Resolved in Xcode 8 beta 2 – IDE Debugging When debugging an app on the Simulator, logs are visible. (26457535)

Xcode 8 Beta 2 Release Notes

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This is no longer an issue in xcode 8.1 (tested Version 8.1 beta (8T46g)). You can remove the OS_ACTIVITY_MODE environment variable from your scheme.

https://developer.apple.com/go/?id=xcode-8.1-beta-rn

Debugging • Xcode Debug Console no longer shows extra logging from system frameworks when debugging applications in the Simulator. (26652255, 27331147)

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In Xcode 10 the OS_ACTIVITY_MODE variable with disable (or default) value also turns off the NSLog no matter what.

So if you want to get rid of the console noise but not of your own logs, you could try the good old printf("") instead of the NSLog since it is not affected by the OS_ACTIVITY_MODE = disable.

But better check out the new os_log API here.

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Please note that for iOS 14 Simulator, the OS_ACTIVITY_MODE=disable will not show any logs using the new Swift Logger. You will have to remove or enable it.

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I read all solutions, nothing worked so far, I am using XCODE 12.5 at the time of writing this response, it's the most annoying thing to see in a debugger with such a heap/flood of unwanted messages.

The solution I did was a lot simpler than most complex ones out there, here is what I did to solve this annoying issue:

No need to use any environment variables etc, otherwise using these as suggested by the previous posts would disable NSLOG output which isn't what you want in such case. I made sure that all my NSLOG would contain a String that I would monitor later on, example:

Previously I used to do:

NSLog(@"Hello World");

Now, I do:

NSLog(@"[Admin]: Hello World");

Whereas "[Admin]" is the name of my program (or whatever string you like other than [Admin]"

(Optional Step) or (Easier), I wrote a function to channel (well; proxy) NSLog into another global function "Log" whereas all my logged would go to that function, and then the Log function would append the "[Admin]" string to the original logging string and also add logging-time and other items I needed etc (similar to WebLogic or any other JAVA logging), this ensure that all logs would follow one standard. ... Here is the million dollar nuclear weapon:

Now, go into your Debugger window, at the bottom you will see a "search" window whereas it says "Filter", enter your string (example; "[Admin]"), press ENTER, and job done.

This way, you will only see the lines you like to see,

https://i.stack.imgur.com/KPYqD.jpg

Also useful when you like to filter out other components, example, for network communication I use more strings that I can filter later on.

In other words, the annoying lines of logs that has nothing to do with your app will always be there, but you choose not to see them using the above command which I hope solves the issue.

Hopefully a good day to all.

H

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This solution has been working for me:

Run the app in the simulator Open the system log (⌘ + /)

This will dump out all of the debug data and also your NSLogs.

To filter just your NSLog statements:

Prefix each with a symbol, for example: NSLog(@"^ Test Log") Filter the results using the search box on the top right, "^" in the case above

This is what you should get:

https://i.stack.imgur.com/HbqrI.png

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