How do you get system diagnostic files from macOS?
Individual crash reports are stored in ~/Library/Logs/CrashReporter but there is a system wide log collection tool called sysdiagnose.

Once you start experiencing the issue, hold down the
4 modifier keys and then press the period "." key. shift+control+option+command+.

After about 15 seconds, a Finder window will open with a sysdiagnose file highlighted. 



This keyboard shortcut simply executes the sysdiagnose command, so if you are familiar with Terminal and want to pass in a process ID, you can get enhanced debugging information about that specific program. The key shortcut calls the tool with no arguments and captures the basic report only.