Spotlight just kinda’ works. Except when it doesn’t. Which is luckily pretty rare, for the use cases that Spotlight was designed for. But when it doesn’t work, you have a few tools that I’ve highlighted over the years to help you out, including articles on shared volumes, manually indexing, disabling Spotlight, and a few others. But what if you need to go in more depth to isolate an issue? For this, Apple has provided us with a tool called mddiagnose, in /usr/bin. In the following command, we’ll run an mddiagnose to dump a bunch of system statistics that we can then look at. Here, we’ll do that to a folder called test in our current working directory:
/usr/bin/mddiagnose -f test
The output is then test.mdsdiagnostic, a directory with a CrashReporter, spindump, Samples, DiagnosticReports, a few system.log exports, and a diagnostic.log.
You can then view your log using the more command (or cat or less or whatevers)
more ~/test.mddiagnostic/diagnostic.log
Here, you’ll see the output of a bunch of scripts that were run. I find that this is the most informational aspect of what I get from the mddiagnose output. Every time I’ve actually fixed an issue here, it’s been with this output.
The other aspect of mddiagnose that I’ve found useful is checking permissions and paths. Here, you can answer the simple question of whether mdutil has permissions to check a path. We’ll do so using the -p option:
mddiagnose -p /Library/Application\ Support/Appifitizer
Enjoy!
