macOS Catalina installer freezes just after choosing disk

I'm trying to install macOS Catalina. Currently I have Mojave, macbook pro 13", mid 2012. System suggested this upgrade so I decided to install it right away :)

When Catalina installer started it asked about accepting license and then to choose disk. After that beachball of death appears i.e. the installer process is frozen (and is marked red in Activity Monitor). After 30m I force killed this process and retried 3 times, so far.

How can I determine what is slowing or stopping my installation?

I found a fix for me. Something told me that a disabled Spotlight might be the reason (I had similar issue long time ago and re-enabling Spotlight did the job).

If you have Spotlight disabled, then re-enable it using this in Terminal:

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

After installation you can disable it once again :) Hope it helps someone.

*Can also make this change in System Preferences > Spotlight > Privacy = Then drag and drop hdd into the window. To undo the action, just click on the hdd, and select the minus symbol. This did the trick for me.

Before you do anything once you launch the Install macOS Catalina app - choose the window menu, show log (Command L) then show all logs (Command 3)

After a failed install, you can look at /var/log/install.log and see where it's getting stuck or at least know the last few things it has done before it gets bogged down.

I'm installing on to a Catalina volume and the install took about 15 minutes on my SSD MacBook (One) that has a 1.1 GHz Intel Core M processor and was made in 2015 (the original small MacBook with retina screen) and the installer runs quite quickly, so my hunch is it's crunching all your apps and settings in pre-check scripts or finding a reason to fsck / file system check your drive.

The logs will let you know what's really being done, though.