I'm getting an error like the following (censored and trimmed to protect proprietary info):
Process: MyExecutable [7150]
Path: /Applications/Company Name/Parent App.app/Contents/PlugIns/MyExecutable
Identifier: MyExecutable
Version: 0
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: MyExecutable [7150]
User ID: 1129915948
Date/Time: 2018-03-27 11:42:12.401 -0400
OS Version: Mac OS X 10.12.6 (16G1212)
Report Version: 12
Anonymous UUID: 013E2942-CED9-22FA-438A-E3D0BA89EB5C
Time Awake Since Boot: 6200 seconds
System Integrity Protection: enabled
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00007fa9bc632b10
Exception Note: EXC_CORPSE_NOTIFY
Termination Signal: Bus error: 10
Termination Reason: Namespace SIGNAL, Code 0xa
Terminating Process: exc handler [0]
VM Regions Near 0x7fa9bc632b10:
MALLOC_TINY 00007fa9bc400000-00007fa9bc600000 [ 2048K] rw-/rwx SM=PRV
--> MALLOC_TINY 00007fa9bc600000-00007fa9bc700000 [ 1024K] rw-/rwx SM=COW
MALLOC_TINY 00007fa9bc700000-00007fa9bc800000 [ 1024K] rw-/rwx SM=PRV
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 ??? 0x00007fa9bc632b10 0 + 140366986816272
1 com.apple.Foundation 0x00007fffa3225051 -[NSConcreteTask waitUntilExit] + 213
2 MyExecutable 0x000000010dcfeb86 _TTSf4gs_gs_g___TF8MyExecutableP33_446BC8CF8CAA764CF050D96869CE3A5A18mySwiftFunctionFTSS7purposeSS18callbackFCSo7ProcessT__T_ + 1254
3 MyExecutable 0x000000010dcfdbb7 _TZFC8MyExecutable12MyClassP33_446BC8CF8CAA764CF050D96869CE3A5A31someSwiftFunctionfT_T_ + 215
4 MyExecutable 0x000000010dcfd985 _TZFC8MyExecutable12MyClass40someSwiftFunctionfT_T_ + 21
5 MyExecutable 0x000000010dcd8e0f main + 241
6 libdyld.dylib 0x00007fffb6ef3235 start + 1
The code in question attempts to run a terminal command by using Process (AKA NSTask in Objective-C; implemented by NSConcreteTask). It's prepared like this:
process.launchPath = "/bin/bash"
process.arguments = ["-c", bashCommand]
process.terminationHandler = callback
process.launch()
process.waitUntilExit()
It runs fine until the call to waitUntilExit. When that runs, the app crashes immediately with an output similar to that above.
For various reasons, I can't run a debugger to test this, but I can print log lines to the console. Why would it crash this hard? I even see a bus error in there for crying out loud...
Synchronous waitUntilExit() and asynchronous completion handler don't work very well together.
If you use the asynchronous completion handler waiting for exit is actually pointless.
Just delete the line
process.waitUntilExit()