Open Radar

 
Summary:
We automate iOS application and use virtual machines to execute UIAutomation tests using iOS Simulator (iOS 9.3). 

Environment:
• Host: Mac Mini (Late 2014) with latest version of EL Capitan onboard; Xcode 7.3 and Simulator with iOS 9.3.
• Guest: VM with latest version of EL Capitan onboard; Xcode 7.3 and Simulator with iOS 9.3. 2 cores, 4Gb RAM (host machine has 8Gb in total), 128Mb VRAM, 60GB HDD.
• Virtualization software: tried VMware, Parallels and VirtualBox.

Problem:
After upgrade to Mac OS 10.11 and Xcode 7.3 from 10.10/Xcode 7.2, Instruments output log lag when we use guest (VM), i.e. when we run tests on guest (using iOS 9.3 simulator) we observe delay between real action on a simulator and appropriate log from Instruments command (http://stackoverflow.com/questions/4191945/can-the-ui-automation-instrument-be-run-from-the-command-line). This delay continuously grows (about a second during the first minute and up to a few minutes after 20 minutes of running tests).

We are also getting the following error message in Console (All Messages):  "instruments: Unable to create Accellerated OpenGL renderer." when tests are running.

We DO NOT observe such problems on host (real) machine, i.e. there is no problem with delay between action on simulator and output log and we also don’t see "instruments: Unable to create Accellerated OpenGL renderer." error message.

We also didn’t experience these problems on previous environment, when we used Mac OS 10.10 and Xcode 7.2 on VM.

One more note, after 10-15 hours of running tests, Instruments takes a lot of RAM (It is compressed by OS and may take up to 20GB or even more) and finally Instruments stops to provide any STDOUT/STDERR.

So, probably Instruments log output buffer or new video system in EL Capitan is a reason of the issue, but we are not sure. 

Steps to Reproduce:
1. Run UIAutomation tests using iOS Simulator (iOS 9.3) on VM (Mac OS with EL Capitan on board) using console.
2. Wait 10-15 minutes while test(s) are running.
3. Look at the simulator screen and output log from Instruments.

Expected Results:
a. Current log output should correspond to the action on the simulator screen (real-time log).
b. no any error messages in Console.

Actual Results:
a. There is a delay between real action on the screen and appropriate log and this delay is growing.
b. "instruments: Unable to create Accellerated OpenGL renderer." error message in Console

Version:
Xcode 7.3 (7D175)
OS X 10.11.4 (15E65)


Notes:


Configuration:
It does occur on EL Capitan with Xcode 7.3 when we use guest VM (tried Parallels, VMware and VirtualBox).
It does NOT occur on EL Capitan with Xcode 7.3 when we use real machine.
It dos NOT occur when we use Mac OS 10.10 and Xcode 7.2 neiter on real machine nor on guest VM.