LLDB launch xcodebuild with xcpretty - ios

Question

I am launching xcodebuild through the lldb debugger so I can alter its execution like:
lldb
# set debugging target
target create /Applications/Xcode.app/Contents/Developer/usr/bin/xcodebuild
# launch process and stop at entry point
process launch -s -- -sdk iphonesimulator -destination 'name=iPhone SE' test
# set a breakpoint
breakpoint set -F "+[IDELaunchParametersSnapshot launchParametersWithSchemeIdentifier:launcherIdentifier:debuggerIdentifier:launchStyle:runnableLocation:debugProcessAsUID:workingDirectory:commandLineArgs:environmentVariables:architecture:platformIdentifier:buildConfiguration:buildableProduct:deviceAppDataPackage:allowLocationSimulation:locationScenarioReference:showNonLocalizedStrings:language:region:routingCoverageFileReference:enableGPUFrameCaptureMode:enableGPUValidationMode:debugXPCServices:debugAppExtensions:internalIOSLaunchStyle:internalIOSSubstitutionApp:launchAutomaticallySubstyle:]"
break command add
po $rcx = (unsigned long)IDEDefaultLauncherIdentifier
po $r8 = (unsigned long)IDEDefaultDebuggerIdentifier
continue
DONE
# resume execution
continue
What I want to achieve is to attach xcpretty to:
process launch -s -- -sdk iphonesimulator -destination 'name=iPhone SE' test
like
process launch -s -- -sdk iphonesimulator -destination 'name=iPhone SE' test || xcpretty
but I can see that obviously that is not the way.
xcodebuild: error: Unknown build action '||'.
Any ideas if that is even possible and if so how ?

Answer 1

Try this
process launch -s -- -sdk iphonesimulator -destination 'name=iPhone SE' test | xcpretty
instead of
process launch -s -- -sdk iphonesimulator -destination 'name=iPhone SE' test || xcpretty
or you can go this way
process launch -s -- -sdk iphonesimulator -destination 'name=iPhone SE' test > output.txt
xcpretty < output.txt

Answer 2

The run-args in lldb's "process launch" do not support piping or redirection operators. If the -c option is set, lldb will get the shell to do shell expansion on the arguments. But that's all the interaction with the shell that lldb supports.
If you need to debug something that is running in a chain of execution, you will have to launch the process chain manually, and attach to the process in the chain after the fact. The way to do this is to start the attach in lldb before launching your process and use the -w option to process attach to tell lldb to attach to the process once it starts up. Then start the process. Unless your system is heavily loaded lldb will generally catch the process early in its startup, so for most debugging tasks you don't miss code you actually care about.