Would be nice if someone (@wkennington?) checked whether #2838 is still a problem. Looking at the other ISOs in osinfo-db it probably shouldn't be.

I think the issue with windows will be fixed with using the joliet extension.

Installation in virt-manager working fine:)

Installation in virt-manager working fine:)

I made a vm in gnome-boxes. I'll see if I can install nixos to a usb and windows and start it eventually, since there was the issue in #2838.

Looking at the wiki page Volume Identifier is strD type, which only supports A-Z, 0-9 and _ characters.

Looking at the wiki page Volume Identifier is strD type, which only supports A-Z, 0-9 and _ characters.

I guess a regex would work for this. Does it not support the dash?
Edit: it must if I was able to boot and build the iso.

No it does not: https://wiki.osdev.org/ISO_9660#String_format

Maybe implementations follow Postel’s law but if the wiki is correct, we can only use [A-Z0-9_]{1,32}.

Perhaps https://wiki.osdev.org/ISO_9660#Rock_Ridge_and_Joliet has something to do with it. I see there's various improvements and extensions. For that matter, I see fedora has volume id's with dashes https://gitlab.com/libosinfo/osinfo-db/-/blob/master/data/os/fedoraproject.org/fedora-31.xml.in#L36. So perhaps there's something we're missing here.

It seems ubuntu even has spaces https://gitlab.com/libosinfo/osinfo-db/-/blob/master/data/os/ubuntu.com/ubuntu-19.04.xml.in#L37 so maybe that documentation isn't an account of improvements

Briefly looking at the ECMA document, it looks like the Joliet format only adds enhanced volume descriptor, which mainly loosens the file and directory identifiers but not the volume identifier.

Not sure if this part of the standard is mostly ignored or Joliet/Rockridge relaxes the constraint but it seems minority of the ISOs found in osinfo-db conform:

$ ack -ch "<volume-id>.*</volume-id>"
2721
ack -ch "<volume-id>[A-Z0-9_]*</volume-id>"
188

(Ok, the content of the tag can be regex, but still only a minority are actual strD.)

Also from man xorriso:

   -volid text
         Specify the volume ID, which most operating systems will consider to be the volume name of the image or medium.
         xorriso accepts any text up to 32 characters, but according to rarely obeyed specs stricter rules apply:
         ECMA-119 demands ASCII characters out of [A-Z0-9_]. Like:
           "IMAGE_23"
         Joliet allows 16 UCS-2 characters. Like:
           "Windows name"
         Be aware that the volume id might get used automatically as the name of the mount point when the medium is inserted into a playful computer system.

Actually, I was reading the ECMA doc wrong. The Volume Identifier described in 8.4.6 is only relevant for Primary Volume Descriptor. Joliet’s Enhanced Volume Descriptor has its Volume Identifier described in section 8.5.5, which specifies it as d1-characters:

7.4.2 c-characters

The characters of the coded graphic character sets identified by the escape sequences in a Supplementary Volume Descriptor are referred to as c-characters.

7.4.2.1 a1-characters

A subset of the c-characters will be referred to as a1-characters. This subset shall be subject to agreement between the originator and the recipient of the volume.

7.4.2.2 d1-characters

A subset of the a1-characters will be referred to as d1-characters. This subset shall be subject to agreement between the originator and the recipient of the volume.

So if I am reading it right, we are indeed not limited by character range in Joliet format, only by the 32 byte size of the field.

@jtojnar Great, thank you for the research. This kind of PR is one that could go wrong in the worst ways without it.