Catalina installation stuck

So mine has been mine has been stuck for about 17 hours at the All black screen with the white Apple logo the progress bar is almost full but has not moved in hours. I am not having the thing where it says setting up mine is basically the screen where it appears that it’s downloading or installing. I’ve tried rebooting but no success. I can’t enter safe mode either, how do I access the menu where I could potentially do a restore from Time Machine? Thank you

In my case the update was stuck for over 60 hours.

I rebooted the iMac into internet recovery and saw that there was not enough space on the hard drive (3TB FD).

Before the upgrade I hat ~350GB space available.

I solved this by creating a bootable MacOS on an USB drive. Booted the iMac from this USB drive. Copied some data (700GB) to another external drive and had ~1TB free space.

After that I started the internet recovery and the upgrade went well in under 1 hour.

My guess is that due to the changed in disk volumes the upgrade may be stuck or very very slow due to less space.

Do I hold the record? My installation took 49 hours!

14.5 hours later...