Recently, when writing new tests and testing on physical devices, eventually (sometimes within a few times of ruing tests or sometimes after hours of ruing tests) each device will start crashing. The only solution I have found is to restart the device and then the tests start ruing fine again.
Here is the console output from Xcode 7.3.1:
2016-07-22 09:17:27.277 XCTRuer[470:164209] Ruing tests...
2016-07-22 09:17:27.280 XCTRuer[470:164209] Unable to load configuration data from specified path /var/folders/83/tbqj_hp908ddc7bn45hcrh_c0000gn/T/com.apple.dt.XCTest/B389F86E-56B0-4131-B52B-8E9A41E2A789/remote-container/tmp/CollaborateUITests-B389F86E-56B0-4131-B52B-8E9A41E2A789.xctestconfiguration; error: The file doesn’t exist.
2016-07-22 09:17:27.281 XCTRuer[470:164209] Looking for test bundles in /var/containers/Bundle/Application/15D4EDF6-C56A-4735-9DEF-57869AE677AC/CollaborateUITests-Ruer.app/PlugIns
2016-07-22 09:17:27.281 XCTRuer[470:164209] Found test bundle at /var/containers/Bundle/Application/15D4EDF6-C56A-4735-9DEF-57869AE677AC/CollaborateUITests-Ruer.app/PlugIns/CollaborateUITests.xctest
2016-07-22 09:17:27.282 XCTRuer[470:164209] Looking for configurations in /var/containers/Bundle/Application/15D4EDF6-C56A-4735-9DEF-57869AE677AC/CollaborateUITests-Ruer.app/PlugIns/CollaborateUITests.xctest
2016-07-22 09:17:27.282 XCTRuer[470:164209] No configurations found, creating a default configuration that will run all tests.
2016-07-22 09:17:27.480 XCTRuer[470:164209] *** Assertion failure in -[XCUIApplication init], /Library/Caches/com.apple.xbs/Sources/XCTest_iOS/XCTest-10112/XCTestFramework/UI Testing/XCUIApplication.m:72
And the pthread_kill:
libsystem_keel.dylib`__pthread_kill:
0x180620114 <+0>: movz x16, #0x148
0x180620118 <+4>: svc #0x80
-> 0x18062011c <+8>: b.lo 0x180620134 ; <+32>
0x180620120 <+12>: stp x29, x30, [sp, #-16]!
0x180620124 <+16>: mov x29, sp
0x180620128 <+20>: bl 0x1806066d8 ; cerror_nocancel
0x18062012c <+24>: mov sp, x29
0x180620130 <+28>: ldp x29, x30, [sp], #16
0x180620134 <+32>: ret
Specifically, why am I seeing Unable to load configuration data from specified path? I do not get this error when the tests run as expected. What is changing on these devices? I have tried deleting the installed app and the XCTest helper app, but once a device starts showing these errors, the only way to solve the problem is to restart the device.
I can still build on a device, but I caot test on a device that starts this until after rebooting the device. Also, I can still run tests on other devices (until the other devices start showing this same error).
Why would this be happening intermittently? I haven't found a specific way to reproduce it except for to continue ruing tests until it randomly occurs again.