iOS app crashes, xcode says 'Lost connection to X's iPhone' when debugging
IosIphoneXcodeCrashIos Problem Overview
My app crashes and I need some advice to find and fix the problem. It is not a device or cable problem because it happens with all devices and not only when debugging. Xcode won't stop on an exception breakpoint the app just simply stops running with no error information. When debugging xcode only says 'Lost connection to X's iPhone'. I have the following log from the device, see MY_CRASHING_APP:
Incident Identifier: 85730E97-BA21-4C72-8AD1-02075A8FD9A7
CrashReporter Key: d9e9eb14ac1801fea11e662a394244d7caf29154
Hardware Model: iPhone4,1
OS Version: iPhone OS 8.0 (12A365)
Kernel Version: Darwin Kernel Version 14.0.0: Tue Aug 19 15:08:02 PDT 2014; root:xnu-2783.1.72~8/RELEASE_ARM_S5L8940X
Date: 2014-09-24 15:02:41 +0200
Time since snapshot: 325 ms
Free pages: 20793
Active pages: 20412
Inactive pages: 10678
Speculative pages: 1757
Throttled pages: 55906
Purgeable pages: 699
Wired pages: 21196
File-backed pages: 30263
Anonymous pages: 2584
Compressions: 76385
Decompressions: 3948
Compressor Size: 81
Uncompressed Pages in Compressor: 61
Page Size: 4096
Largest process: MY_CRASHING_APP
Processes
Name | <UUID> | CPU Time| rpages| purgeable| recent_max| lifetime_max| fds | [reason] | (state)
coreduetd <675ac3d39b193f9bba42896818431859> 0.049 124 0 - 391 50 [vnode-limit] (daemon) (idle)
homed <77bcbc47e2723e269b0ff9d115658259> 0.052 146 0 - 458 50 [vnode-limit] (daemon) (idle)
gamed <a51b1ad16b693a75aeaaf2166e7b1b0b> 0.049 38 0 - 74 50 [vnode-limit] (daemon) (idle)
lsd <72b4494834d3357bb8aa32fd5b5c8e83> 0.068 161 0 - 368 50 [vnode-limit] (daemon)
InCallService <88e149874b1c35f2b8adbeee958d7258> 18.461 1289 0 - 3238 50 [vnode-limit] (resume) (continuous)
MY_CRASHING_APP <1542054cd5393df29827ca1a6bd34e04> 59.116 24504 600 - 29490 1600 [vnode-limit] (frontmost) (resume)
ptpd <c0bc1e573edb3bcebea0f3140a139421> 3.442 878 0 - 1634 50 (daemon)
BTServer <1b7372b3ae393847b1c3ccaa720e991e> 3.057 393 0 - 1437 50 (daemon)
lockdownd <bb602fb4b5ac3b51af2d22c4fdce9778> 11.306 271 0 - 761 50 (daemon)
imagent <01ebc2c08d7f36059714967efaa86e78> 19.892 585 0 - 1286 50 (daemon)
locationd <9727e24fbe4f357cb27d7bc8cf882c93> 489.694 1665 0 - 3586 50 (daemon)
identityservices <13c2b979d6433252a011087be05e1aa5> 22.999 696 0 +2 1585 50 (daemon)
discoveryd <dff5d0d2edf43b45b0c7fbd4a3e1b677> 93.758 589 0 - 1077 100 (daemon)
wifid <5fb79228aa653a9bb725217b9cb891e6> 63.420 571 0 - 1098 50 (daemon)
iaptransportd <ae70565455de38f3aab8993e9d109207> 7.713 306 0 - 579 50 (daemon)
mediaserverd <b5ba58774a853d43a17559ae76a6f918> 649.476 1025 64 - 6134 50 (daemon)
syslogd <a5a138dc01cd34d19bbe336c03099ce7> 40.100 201 0 - 384 50 (daemon)
powerd <b3163caaebd53f7aa42634836472ea04> 43.199 231 0 - 474 50 (daemon)
apsd <17af2320ccfb3e668b6455b95b4612ce> 37.461 631 0 - 1445 50 (daemon)
networkd <a657abe0ce803333b886876a8f7a36e0> 77.271 596 0 - 1297 50 (daemon)
dataaccessd <db655c44d5c830dc9e5f34f7edcb17a4> 243.259 1777 0 - 3097 100 (daemon)
vmd <88cebb23d0f1344db23e1896b1787f2d> 0.505 204 0 - 617 50 (daemon)
iapd <e84bb9b7cf7530babc36c6ca37b7f345> 11.963 453 0 - 1673 50 (daemon)
syslog_relay <9e18dbcbcc07374e9d14c732b8dabad2> 1.424 98 0 - 189 50 (daemon)
voiced <2d24fa3e32533f2f8298743eaf348d63> 0.179 210 0 - 581 50 (daemon)
itunesstored <d50d5b1c3f693694a2eee878aae8facf> 0.573 908 0 - 1759 50 (daemon)
SpringBoard <3e0aacaca7103aa09a71e5c9fee3e012> 841.081 7088 29 - 16912 50
backboardd <117d65aca8ce3ba68c7fd87d9ab81da6> 3424.058 6678 625 - 4409 50 (daemon)
UserEventAgent <2f6c74a697943aed899faebac621e4c3> 316.816 848 0 - 2101 200 (daemon)
configd <64e4db8bced23463b446c4b7c868fcfa> 31.906 416 0 - 933 50 (daemon)
fseventsd <a393d343a7533860b5c1eddb922a33f1> 20.088 405 0 - 805 50 (daemon)
fairplayd.H1 <c3856f0573fb3f9887721a239507f28b> 30.647 159 0 - 1096 50 (daemon)
assertiond <032107d4db2b36ddac986060d8c62f73> 26.282 289 0 - 702 50 (daemon)
wirelessproxd <ba82fe3b38f63f2b8b8807a2bf97aadd> 1.071 179 0 - 643 50 (daemon)
distnoted <e8f9e76e751838a880dad2d4a953f814> 4.457 193 0 - 254 50 (daemon)
discoveryd_helpe <84abc0c6dd5b37a8b2c8323881e16da7> 0.493 123 0 - 466 50 (daemon)
ubd <5f4f0054821e3b41b543a4d9f4176291> 9.040 730 0 - 1540 50 (daemon)
filecoordination <68a3848887853629adae42f5828a5443> 2.731 251 0 - 649 100 (daemon)
aggregated <ab0d307a392f36cc827709d24c4b8696> 1335.558 1081 0 - 1688 50 (daemon)
DTMobileIS <086152f142ac30a686a172b148d38fbc> 109.156 474 0 - 1724 50 (daemon)
touchsetupd <d8aabe65f2d23f6ab7704bbccc6c2ba1> 0.388 158 0 - 464 50 (daemon)
cfprefsd <6e5dcfe209183c719091d07edad590da> 0.150 166 0 - 320 50 (daemon)
accountsd <9eb0309b021033c6b24ce65da48fa228> 0.665 595 0 - 1909 50 (daemon)
CommCenter <0e1ced0eddce346ba27e9f54886ef025> 669.306 1543 0 - 4623 50 (daemon)
notifyd <7beaf472572334d4989a40473776f635> 61.698 272 0 - 309 50 (daemon)
ReportCrash <b36d5780860a3dfcbb146b2cc6bca339> 0.062 146 0 - 443 50 (daemon)
**End**
UPDATE:
It turned out to be a memory issue. The app was allocating a lot of memory very quickly and the OS terminated the app. It was strange that Xcode did not log a memory warning while in Instruments show that the app received a LOT of warnings. Other apps that used the same amount of memory got away with no memory warnings. My guess is that those were not allocating memory at such a fast rate.
The app was running on an iPhone 4S and it got killed at around 90MB memory usage.
What confused me is other out of memory issues all had Purgeable pages: 0. So I'm guessing this is not exactly an out of memory but too much memory usage in a short time?
Ios Solutions
Solution 1 - Ios
Just chipping in for anyone else who is struggling on this one.
For me the solution was to restart my device.
Solution 2 - Ios
I had this same issue when loading a bunch of very large images (5000px x 5000px) in UIImages. Luckily the images were not supposed to be anywhere near that big and I just needed to resize them.
Solution 3 - Ios
This bug appears frequently since I switched on iOS 11 Beta. Sometimes restarting the device works, sometimes my computer...
Solution 4 - Ios
Yes, it is a memory issue, or you have opened too many threads. I have met this problem before. The problem I met like this:
When I delete a photo, which may cost about 0.2s, I would like to show a toast(MBProgressHUD) to user, and GCD to hide the toast after deleting.
When I tried to delete 100 photos, it is okay. However, when I tried to delete 200 photos, the app might be crashed. When I tried to delete 300 photos, the iPhone always restart itself.
Solution 5 - Ios
Posting for posterity, as I recently experienced this 'crash' and it wasn't due to memory issues as others have suggested:
In rare cases, this can be an issue with the cord used to connect the iPhone to the computer. I had a faulty lightning cable, that would sporadically lose connection to my mac. The solution was to by a new one!
Solution 6 - Ios
As Andy Darwin suggested, it is a memory issue.
I had this problem on older devices when adding an UIImageView with animationImages.
Solution 7 - Ios
In my case, I use UICollectionView to show a bunch of photos and when I want to perform reloadData to the view, crash occurs, while the memory usage is not that high (less than 100M). Besides memory issue, I think reloadData of UICollectionView or UITableView may cause this, too.
Solution 8 - Ios
Just to add that I had the same issue running my app both on and old Ipad 3 and Iphone 6. What ended up being the problem was I had accidentally saved 2 images of the project as a 40mb and a 20mb version. So it was a memory issue. I downsized them as 1mb each, and issue solved.
Solution 9 - Ios
Using Big Sour with XCode 12.2
- Create a file called .lldbinit on your home directory (~)
- Add this line to the file:
settings set plugin.process.gdb-remote.packet-timeout 300 - Restart Xcode and try again