System hangs when creating bootable disk drive I followed the instructions provided in this answer which explains how to make an El Capitan bootable disk from a system running Catalina

I copied the commands exactly as prescribed, reproduced here:

pkgutil --expand /Volumes/Install\ OS\ X/InstallMacOSX.pkg ~/Desktop/El\ Capitan
diskutil eject Install\ OS\ X
cd ~/Desktop/El\ Capitan
hdiutil attach InstallMacOSX.pkg/InstallESD.dmg  -noverify -nobrowse -mountpoint /Volumes/esd
sudo asr restore -source /Volumes/esd/BaseSystem.dmg -target /Volumes/MyVolume -noprompt -noverify -erase
diskutil rename OS\ X\ Base\ System Install\ El\ Capitan
rm /Volumes/Install\ El\ Capitan/System/Installation/Packages
cp -rp /Volumes/esd/Packages /Volumes/Install\ El\ Capitan/System/Installation
cp -rp /Volumes/esd/BaseSystem.chunklist /Volumes/Install\ El\ Capitan/
cp -rp /Volumes/esd/BaseSystem.dmg /Volumes/Install\ El\ Capitan/
hdiutil detach /Volumes/esd
sudo bless --folder /Volumes/Install\ El\ Capitan/System/Library/CoreServices --label Install\ El\ Capitan
cp /Volumes/Install\ El\ Capitan/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/InstallAssistant.icns /Volumes/Install\ El\ Capitan/.VolumeIcon.icns
diskutil eject Install\ El\ Capitan


However it hangs at the last line. Here is the output:

pkgutil --expand /Volumes/Install\ OS\ X/InstallMacOSX.pkg ~/Desktop/El\ Capitan
diskutil eject Install\ OS\ X
cd ~/Desktop/El\ Capitan
hdiutil attach InstallMacOSX.pkg/InstallESD.dmg  -noverify -nobrowse -mountpoint /Volumes/esd
sudo asr restore -source /Volumes/esd/BaseSystem.dmg -target /Volumes/MyVolume -noprompt -noverify -erase
diskutil rename OS\ X\ Base\ System Install\ El\ Capitan
rm /Volumes/Install\ El\ Capitan/System/Installation/Packages
cp -rp /Volumes/esd/Packages /Volumes/Install\ El\ Capitan/System/Installation
cp -rp /Volumes/esd/BaseSystem.chunklist /Volumes/Install\ El\ Capitan/
cp -rp /Volumes/esd/BaseSystem.dmg /Volumes/Install\ El\ Capitan/
hdiutil detach /Volumes/esd
sudo bless --folder /Volumes/Install\ El\ Capitan/System/Library/CoreServices --label Install\ El\ Capitan
cp /Volumes/Install\ El\ Capitan/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/InstallAssistant.icns /Volumes/Install\ El\ Capitan/.VolumeIcon.icns
diskutil eject Install\ El\ Capitan
Could not open package for expansion: /Volumes/Install OS X/InstallMacOSX.pkg
Unable to find disk for Install OS X
/dev/disk3              GUID_partition_scheme           
/dev/disk3s1            EFI                             
/dev/disk3s2            Apple_HFS                       /Volumes/esd
Password:

    Validating target...done
    Validating source...done
    Retrieving scan information...done
    Validating sizes...done
    Restoring  ....10....20....30....40....50....60....70....80....90....100
    Restored target device is /dev/disk2s1.
    Remounting target volume...done

asr: Couldn't personalize volume /Volumes/OS X Base System - State not recoverable
Volume on disk2s1 renamed to Install El Capitan


Does anyone have any idea why that might happen?
The asr command can be replaced by using the Disk Utility to restore to a sparse image. Since the sparse image is using a MBR partitioning scheme, image can then be cloned to the external drive by using the dd command. The updated procedure has been added to the answer given as a link in your question.