[Bug 1848856] Re: Upgrade from 19.04 to 19.10 with zfs on root fails with grub syntax error

[jpb]

Problem identified.  The variable intrd_device contains a \r at the end
of the variable.  When concatenating the variable with the subsequent
variables, it effectively truncates the subsequent data in the echo
return.

Preceding the if statement, I inserted the following:

    # remove the trailing \r from the variable
    initrd_device=$(echo ${initrd_device} | tr -d '\r')

This removed the trailing \r, allowing the full set of data to be
returned.

I tested this fix on my own system by modifying the 10_linux_zfs script
in /etc/grub.d.  The grub.cfg is now successfully generated and apt/dpkg
are able to perform an update-grub.

10_linux_zfs attached.

** Attachment added: "10_linux_zfs"
   https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1848856/+attachment/5299058/+files/10_linux_zfs

-- 
You received this bug notification because you are a member of Ubuntu
Sponsors Team, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/1848856

Title:
  Upgrade from 19.04 to 19.10 with zfs on root fails with grub syntax
  error

Status in grub2 package in Ubuntu:
  Confirmed

Bug description:
  At the end of the upgrade from 19.04 to 19.10, the post process of the
  update-grub reports:

  Syntax error at line 185
  Syntax errors are detected in generated GRUB config file.
  Ensure that there are no errors in /etc/default/grub
  and /etc/grub.d/* files or please file a bug report with
  /boot/grub/grub.cfg.new file attached.
  run-parts: /etc/kernel/postinst.d/zz-update-grub exited with return code 1
  dpkg: error processing package linux-image-5.3.0-18-generic (--configure):
   installed linux-image-5.3.0-18-generic package post-installation script subprocess returned error exit status 1
  Errors were encountered while processing:
   friendly-recovery
   grub-efi-amd64
   grub-efi
   grub-efi-amd64-signed
   shim-signed
   linux-image-5.3.0-18-generic

  The system used https://github.com/zfsonlinux/zfs/wiki/Ubuntu-18.04
  -Root-on-ZFS to add zfs on root to a 19.04 system.

  The syntax error in grub.cfg.new is an extra } on line 185.  However,
  comparing the grub.cfg.new to the previously generated grub.cfg under
  19.04, there is a significant quantity of configuration missing.

  Manually running update-grub generates the same error.
  /etc/default/grub is the only file changed from default installation
  to include zswap.  This file was not changed prior to upgrade.

  The error is reported during the processing of
  /etc/grub.d/10_linux_zfs which is dated October 11.  I attempted the
  upgrade on 10/18 and have done multiple updates to get the latest
  kernel and remove old kernels prior to the upgrade.  So, I believe the
  problem is with one of the upgrade modules.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1848856/+subscriptions