Get unified log messages via sysdiagnose

I'm trying to use unified logging to log messages and retrieve them from a device for inspection. I created a new

OSLog

instance with

let logDebug = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: " debug")

Then I log messages with

os_log("%@", log: logDebug, type: OSLogType.debug, String(format:message, arguments: formatArgs))

This works fine in the Xcode console. It's supposed to be possible to retrieve these logs from an Xcode device by

• Doing a sysdiagnose (as Apple explains here)
• Transferring the sysdiagnose to a Mac, and then
• Inspecting the log (in

  system_logs.logarchive

  ) with Console.app or the

  log

  command line tool.

When I do this, none of my logs are shown. No logs with the expected subsystem (bundle ID) are shown.

However, if I examine the log files in

system_logs.logarchive

directly via

grep

or

vim

, the messages are present. So they're in the logs, but for some reason neither Console.app nor

log

will show them. I made sure that Console.app is set to show "all messages" and I haven't entered any search terms.

What step am I missing, or what detail needs to be different?