file command produces different results in 18.04 vs 16.04

[halogen2]

Just downloaded the new Xubuntu 18.04 beta 2 ISO, and was going to customise it, but my LiveCD customisation script complained that it's not a valid CD image.

Turns out it's because of the result of the first command here -

$ file -b --mime-type xubuntu-18.04-beta2-desktop-amd64.iso
application/octet-stream

$ file xubuntu-18.04-beta2-desktop-amd64.iso
xubuntu-18.04-beta2-desktop-amd64.iso: DOS/MBR boot sector; partition 2 : ID=0xef, start-CHS (0x3ff,254,63), end-CHS (0x3ff,254,63), startsector 2716460, 4672 sectors

In 16.04 with the same file, I get this -

$ file -b --mime-type xubuntu-18.04-beta2-desktop-amd64.iso
application/x-iso9660-image

$ file xubuntu-18.04-beta2-desktop-amd64.iso
xubuntu-18.04-beta2-desktop-amd64.iso: DOS/MBR boot sector ISO 9660 CD-ROM filesystem data (DOS/MBR boot sector) 'Xubuntu 18.04 LTS amd64' (bootable); partition 2 : ID=0xef, start-CHS (0x3ff,254,63), end-CHS (0x3ff,254,63), startsector 2716460, 4672 sectors

Why the difference?

[dino99]

a think you get the usual output: an alpha/beta image is not a final image (not yet released, so no trusted)

[halogen2]

a think you get the usual output: an alpha/beta image is not a final image (not yet released, so no trusted)

But I get the same discrepancy with the official Xubuntu 16.04 release ISO.

[dino99]

Possible explication: https://askubuntu.com/questions/8064...-xubuntu-16-04

[halogen2]

Possible explication:

Nope. That is unrelated to the behavior of the file command.

[zika]

In 18.04 do:

apt changelog file

[halogen2]

Thanks zika, that looks useful - it downloads and displays http://changelogs.ubuntu.com/changel...32-2/changelog.
(For comparison, 16.04 has file version 5.25-2ubuntu1.)

What are we looking for in there?

[halogen2]

As a test, I tried building the 16.04's version of file on 18.04. The result works same as in 16.04.

I'm thinking the change in behavior is a bug.

Edit: Filed https://bugs.launchpad.net/ubuntu/+s...e/+bug/1763570

[flocculant]

As a test, I tried building the 16.04's version of file on 18.04. The result works same as in 16.04.

I'm thinking the change in behavior is a bug.

Edit: Filed https://bugs.launchpad.net/ubuntu/+s...e/+bug/1763570

Have you tested this with ubuntu itself?

Edit : if something is likely to not be 'Xubuntu' eg not Xfce then I try to test it with Ubuntu as well - less chance of them blaming us then Also - if it is in fact a regression - you can tag bugs as such.

[halogen2]

Have you tested this with ubuntu itself?

No I only have Xubuntu set up at the moment.