It happens in new Xcode7 beta:
CompileAssetCatalog /Users/admin/Library/Developer/Xcode/DerivedData/InstaAd-ddgdnbxlpxipirebpndfmgrxspel/Build/Products/Debug-iphoneos/InstaAd.app InstaAd/Images.xcassets
cd /Users/admin/Documents/git/InstaAdIOS/InstaAd
export PATH="/Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Applications/Xcode-beta.app/Contents/Developer/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Applications/Xcode-beta.app/Contents/Developer/usr/bin/actool --output-format human-readable-text --notices --warnings --export-dependency-info /Users/admin/Library/Developer/Xcode/DerivedData/InstaAd-ddgdnbxlpxipirebpndfmgrxspel/Build/Intermediates/InstaAd.build/Debug-iphoneos/InstaAd.build/assetcatalog_dependencies.txt --output-partial-info-plist /Users/admin/Library/Developer/Xcode/DerivedData/InstaAd-ddgdnbxlpxipirebpndfmgrxspel/Build/Intermediates/InstaAd.build/Debug-iphoneos/InstaAd.build/assetcatalog_generated_info.plist --app-icon AppIcon --launch-image LaunchImage --compress-pngs --enable-on-demand-resources YES --filter-for-device-model iPhone7,2 --filter-for-device-os-version 8.4 --target-device iphone --target-device ipad --minimum-deployment-target 8.0 --platform iphoneos --compile /Users/admin/Library/Developer/Xcode/DerivedData/InstaAd-ddgdnbxlpxipirebpndfmgrxspel/Build/Products/Debug-iphoneos/InstaAd.app /Users/admin/Documents/git/InstaAdIOS/InstaAd/InstaAd/Images.xcassets
2015-08-10 14:25:53.366 IBCocoaTouchImageCatalogTool[1054:10336] CoreUI(DEBUG): CSIGenerator using 'LZVN' Compression coreui version (358.000000)
2015-08-10 14:25:56.449 ibtoold[675:6100] An uncaught exception was raised
2015-08-10 14:25:56.450 ibtoold[675:6100] The agent crashed
Application Specific Information:
CoreSimulator 179 - Device: IBSimDeviceTypeiPad1x - Runtime: iOS 9.0 (13A4325c) - DeviceType: IBSimDeviceTypeiPad1x
Thread 6 Crashed:: TDRenditionsDistiller._distill:
0 com.apple.CoreFoundation 0x000000010bc03f61 __CFBasicHashDrain + 353
1 com.apple.CoreFoundation 0x000000010bbf4a1c CFRelease + 300
2 com.apple.CoreFoundation 0x000000010bc03f42 __CFBasicHashDrain + 322
3 com.apple.CoreFoundation 0x000000010bbf4a1c CFRelease + 300
4 com.apple.ImageIO.framework 0x000000010d7f8028 modifyJPEG + 2859
5 com.apple.ImageIO.framework 0x000000010d6079b8 CGImageDestinationCopyImageSource + 576
6 com.apple.CoreThemeDefinition 0x000000010dbfcec9 -[TDSimpleArtworkRenditionSpec createCSIRepresentationWithCompression:colorSpaceID:document:] + 1690
7 com.apple.CoreThemeDefinition 0x000000010dc0555b -[TDRenditionsDistiller _distill:] + 609
8 com.apple.Foundation 0x000000010b2c73ab __NSThread__start__ + 1198
9 libsystem_pthread.dylib 0x000000010d236268 _pthread_body + 131
10 libsystem_pthread.dylib 0x000000010d2361e5 _pthread_start + 176
11 libsystem_pthread.dylib 0x000000010d23441d thread_start + 13
Last command:
_ON_QUEUE_sendMessage:toChannelReturningError:during:
Backtrace of last command:
0 0x00000001111c69f6 -[IBAbstractPlatformToolProxy _ON_QUEUE_sendMessage:toChannelReturningError:during:] (in IDEInterfaceBuilderKit)
1 0x00000001111c68bb __74-[IBAbstractPlatformToolProxy sendMessage:toChannelReturningError:during:]_block_invoke (in IDEInterfaceBuilderKit)
2 0x00007fff8c046c13 _dispatch_client_callout (in libdispatch.dylib)
3 0x00007fff8c047e5e _dispatch_barrier_sync_f_invoke (in libdispatch.dylib)
4 0x000000011007aabc DVTDispatchSync (in DVTFoundation)
5 0x00000001111c67de -[IBAbstractPlatformToolProxy sendMessage:toChannelReturningError:during:] (in IDEInterfaceBuilderKit)
6 0x000000011aae2526 (in IDEInterfaceBuilderCocoaTouchIntegration)
7 0x000000011aacda8b (in IDEInterfaceBuilderCocoaTouchIntegration)
8 0x000000011111dbf3 __84-[IBICAbstractPlatformAdapter compileSelectedItems:options:queue:completionHandler:]_block_invoke (in IDEInterfaceBuilderKit)
9 0x000000011007abb0 __DVTDispatchAsync_block_invoke (in DVTFoundation)
10 0x00007fff8c04b323 _dispatch_call_block_and_release (in libdispatch.dylib)
11 0x00007fff8c046c13 _dispatch_client_callout (in libdispatch.dylib)
12 0x00007fff8c052cbf _dispatch_main_queue_callback_4CF (in libdispatch.dylib)
13 0x00007fff8d58b3f9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ (in CoreFoundation)
14 0x00007fff8d54668f __CFRunLoopRun (in CoreFoundation)
15 0x00007fff8d545bd8 CFRunLoopRunSpecific (in CoreFoundation)
16 0x00000001111912bc -[NSRunLoop(IBIDEFoundationRunLoopAdditions) ib_spinRunLoopInMode:whileBlockExecutesConcurrently:] (in IDEInterfaceBuilderKit)
17 0x00000001111914ba -[NSRunLoop(IBIDEFoundationRunLoopAdditions) ib_spinRunLoopInMode:waitingForSemaphore:] (in IDEInterfaceBuilderKit)
18 0x000000010fde887a (in ibtoold)
19 0x000000010fde9e30 (in ibtoold)
20 0x000000010fdea2b0 (in ibtoold)
21 0x000000010fdf7e6f (in ibtoold)
22 0x000000010fdf8523 (in ibtoold)
23 0x000000010fdf83fa (in ibtoold)
24 0x000000010fde76c2 (in ibtoold)
25 0x000000010fdf7a64 (in ibtoold)
26 0x000000010fdf6cc9 (in ibtoold)
27 0x00007fff8eb585c9 start (in libdyld.dylib)
2015-08-10 14:25:56.451 ibtoold[675:6100] (
0 CoreFoundation 0x00007fff8d63803c __exceptionPreprocess + 172
1 libobjc.A.dylib 0x00007fff980b976e objc_exception_throw + 43
2 CoreFoundation 0x00007fff8d637bd9 -[NSException raise] + 9
3 IDEInterfaceBuilderKit 0x00000001111c5b55 -[IBAbstractPlatformToolProxy _errorByAddingAdditionalCrashInformationToError:orRaiseIfNeededOnFailure:shouldRaiseOnFailures:waitForCrashLog:] + 1632
4 IDEInterfaceBuilderKit 0x00000001111c54cb -[IBAbstractPlatformToolProxy errorByAddingAdditionalCrashInformationToError:orRaiseIfNeededOnFailure:] + 98
5 IDEInterfaceBuilderKit 0x00000001111c6a90 -[IBAbstractPlatformToolProxy _ON_QUEUE_sendMessage:toChannelReturningError:during:] + 227
6 IDEInterfaceBuilderKit 0x00000001111c68bb __74-[IBAbstractPlatformToolProxy sendMessage:toChannelReturningError:during:]_block_invoke + 38
7 libdispatch.dylib 0x00007fff8c046c13 _dispatch_client_callout + 8
8 libdispatch.dylib 0x00007fff8c047e5e _dispatch_barrier_sync_f_invoke + 57
9 DVTFoundation 0x000000011007aabc DVTDispatchSync + 62
10 IDEInterfaceBuilderKit 0x00000001111c67de -[IBAbstractPlatformToolProxy sendMessage:toChannelReturningError:during:] + 393
11 IDEInterfaceBuilderCocoaTouchIntegration 0x000000011aae2526 IBUISegmentConfiguration + 6975
12 IDEInterfaceBuilderCocoaTouchIntegration 0x000000011aacda8b IBUIControlEventTypeToUIControlEventMask + 17323
13 IDEInterfaceBuilderKit 0x000000011111dbf3 __84-[IBICAbstractPlatformAdapter compileSelectedItems:options:queue:completionHandler:]_block_invoke + 230
14 DVTFoundation 0x000000011007abb0 __DVTDispatchAsync_block_invoke + 69
15 libdispatch.dylib 0x00007fff8c04b323 _dispatch_call_block_and_release + 12
16 libdispatch.dylib 0x00007fff8c046c13 _dispatch_client_callout + 8
17 libdispatch.dylib 0x00007fff8c052cbf _dispatch_main_queue_callback_4CF + 861
18 CoreFoundation 0x00007fff8d58b3f9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
19 CoreFoundation 0x00007fff8d54668f __CFRunLoopRun + 2159
20 CoreFoundation 0x00007fff8d545bd8 CFRunLoopRunSpecific + 296
21 IDEInterfaceBuilderKit 0x00000001111912bc -[NSRunLoop(IBIDEFoundationRunLoopAdditions) ib_spinRunLoopInMode:whileBlockExecutesConcurrently:] + 500
22 IDEInterfaceBuilderKit 0x00000001111914ba -[NSRunLoop(IBIDEFoundationRunLoopAdditions) ib_spinRunLoopInMode:waitingForSemaphore:] + 131
23 ibtoold 0x000000010fde887a ibtoold + 10362
24 ibtoold 0x000000010fde9e30 ibtoold + 15920
25 ibtoold 0x000000010fdea2b0 ibtoold + 17072
26 ibtoold 0x000000010fdf7e6f ibtoold + 73327
27 ibtoold 0x000000010fdf8523 ibtoold + 75043
28 ibtoold 0x000000010fdf83fa ibtoold + 74746
29 ibtoold 0x000000010fde76c2 ibtoold + 5826
30 ibtoold 0x000000010fdf7a64 ibtoold + 72292
31 ibtoold 0x000000010fdf6cc9 ibtoold + 68809
32 libdyld.dylib 0x00007fff8eb585c9 start + 1
33 ??? 0x0000000000000002 0x0 + 2
)
Command /Applications/Xcode-beta.app/Contents/Developer/usr/bin/actool failed with exit code 255
How to solve this issue?
That happened because of JPG images in assets catalog, so I imported jpg images directly in the project, and now it works
I had the same issue with Xcode V7b6 and JPG images in assets. Strangely this was working for some JPGs but not for others.
Then I've looked at the JPGs and their color profile, exif data and other meta stuff and indeed removing these data (via GraphicConverter) solved it for us and Xcode now builds fine.
Pdf files in image assets will cause this error. I use png files for @1x @2x @3x images and Xcode works fine.
This error happened with me because the image name contained some unsupported characters (it was saved by Xcode as c71a25e%2FÍcone-XPTO Imagem - 120x120.png, even when placed in .xcassets).
Changing the image name solved this error for me.
Sometimes you should uncheck de "alpha" option to export your png images to Xcode. That solve my problem.
Open "Preview" app - File - Export - Uncheck "alpha" option, then replace your old images in Xcode project.
I was experiencing this issue as well, and replaced the XC Assets with plain .JPG files. Solved it for me.
However, I just installed the GM seed release of Xcode 7 and built with the XC assets catalog, and am no longer experiencing the error. So it appears to have been fixed.
For all beta versions of Xcode you should go to Preferences->Locations and make sure that the command line tools point to the right version & that the Derived data and Archives point in a different folder that stable Xcode is
Had this actool error building a simple Sticker Pack in Xcode 8 Beta 6.
Seems to be a known error with animated stickers that should be fixed soon.
Simple restart of Xcode fixed the error for me.
来源：https://stackoverflow.com/questions/31918339/command-applications-xcode-beta-app-contents-developer-usr-bin-actool-failed-wi