I got the same error on my system when running
apt-get install --reinstall initramfs-tools
By running
apt-get install initramfs-tools
it complained of not being able to create a file called /var/tmp/mkinitramfs-FW_XXXXXX
This was because the folder
/var/tmp
didn't exist... I recreated that and both commands above worked fine again
I got the same error on my system when running
apt-get install --reinstall initramfs-tools
By running mkinitramfs- FW_XXXXXX
apt-get install initramfs-tools
it complained of not being able to create a file called /var/tmp/
This was because the folder
/var/tmp
didn't exist... I recreated that and both commands above worked fine again