TomK wrote:
> Since I began using USB flash media for the installation disk, I have
> always simply downloaded DVD-1.iso, used 'dd' to write it to the USB,
> booted with it, and installed Debian!
Indeed: I was successful in this way, with both Debian Stretch and Devuan Ascii.
This should be reported as bug towards package "debian-cd".
You could try this proposal from
https://askubuntu.com/questions/671159/bootable-usb-needs-cd-rom
Once I get the "Your installation CD-ROM couldn't be mounted..."
message and I'm back at the main Ubuntu Server install screen, I
simply plugged the USB thumbdrive out, then plugged it in again,
and then after pressing the "detect CD" option, I got "The CD-ROM
autodetection was successful... The installation will now continue."
... and so the installation continued.
(The other proposals on that page are quite questionable.)
+1
If this helps, then i'd bet on a race condition between kernel device
detection and Debian's search for the filesystem with its favorite
marker file. (That's how mounting "CDROM" is supposed to work. Afaik
it is well aware that "CDROM" can be a /dev/sdX rather than a /dev/srX.)
I have a system without a CD drive at all. If I get time over the weekend, I may try this (including unplug/replug). (Curiosity may be hard on cats, but Humans might survive).
Have a nice day :)
Thomas
Kenneth Parker