unclear error message: "failed to fill whole buffer"

[pjvleeuwen]

Since I am a new FCOS user I might have a nice uninformed perspective. Via some tickets I will share some problems I ran into, in the hope that others might find them and be helped by it.

Purpose of this specific ticket is to document an unclear error message that I ran into.

Steps to reproduce:

• burn to USB stick : fedora-coreos-32.20201018.3.0-live.x86_64.iso
• add to other USB stick : an IGN file with these contents:

variant: fcos version: 1.1.0 passwd: users: - name: core ssh_authorized_keys: - ssh-rsa AAAA....

• boot from the first USB stick
• mount the second USB stick
• run sudo coreos-installer install /dev/sda --image-file /var/home/core/mnt/my.ign

This results in the output lines:

Error: decoding first MiB of image Caused by: failed to fill whole buffer

The only link I found when Googling on this was :+1:
https://github.com/coreos/fedora-coreos-streams/issues/158#issuecomment-672013148

I suspect that the problem is that I do not define any partitioning in my IGN file. The point of this ticket is that (whatever the cause) it should be more clear from the error message. The current message leaves me guessing.

[bgilbert]

Thanks for the report. You're right that the error message should be improved. The problem is that you're passing --image-file instead of --ignition-file.

Moving to coreos-installer.

[pjvleeuwen]

@bgilbert Thank you for your quick response. Indeed this was the wrong argument by mistake. I only notice it now that you mention it. Anybody else googling for "Error: decoding first MiB of image Caused by: failed to fill whole buffer" might still find this ticket and be helped by it. Thanks!