Ubuntu 16.04

I'm getting this apt update error:

AppStream system cache was updated, but problems were found: 
Metadata files have errors: /var/cache/app-info/xmls/fwupd.xml

I have previously run:

sudo apt install appstream/xenial-backports
sudo apt update
sudo apt upgrade

The above error still exists.


Following the comments, what solved this for me was:

# rm /var/cache/app-info/xmls/fwupd.xml
# appstreamcli refresh --force
AppStream cache update completed successfully.
# apt update

Everything seems fine now.

Should also add that I have version 0.10.6 installed from xenial/back-ports.

  • Hope you're more lucky than me. Tried that a few weeks ago, then it appeared to be fixed, but the problem was back after a few days. – e2-e4 Jul 24 '18 at 17:28
  • @RingØ In that case, fingers crossed but so far so good – smac89 Jul 24 '18 at 17:38
  • Unfortunately, after a shutdown and restart a few hours later the problem is back. – e2-e4 Jul 25 '18 at 0:33
  • @RingØ What version do you have? Mine is AppStream CLI tool version: 0.10.6 – smac89 Jul 25 '18 at 0:45
  • The same on ubuntu 16.04 fully patched. Did you do a cold shutdown, then restart after some time, and apt update? – e2-e4 Jul 25 '18 at 1:11

I found that the error described in your question is caused by a typo in /var/cache/app-info/xmls/fwupd.xml.

My fix procedure:

  1. Open this file on the terminal with command sudo gedit /var/cache/app-info/xmls/fwupd.xml. I am using the gedit text editor here. You can use any text editor that you are comfortable with.
  2. Goto line 265 which says <checksum filename="Firmware_SF30&SN30_Pro_V1.26.dat" target="content" type="sha1">3ef2bdee8aca2a45b9f53b4d4cce9722523f57f8</checksum>. All I did to fix the error was to correct the typo SF30&SN30 to SF30&amp;SN30. That is the symbol & should be changed to &amp;.
  3. Finally, save the file and exit.

To check if successful, run on terminal sudo apt update. The error should not be there. But if it was still there, I ran the command appstreamcli refresh --force and then sudo apt update. By this stage, I no longer encountered the error during the same login session.

Additional notes:

  1. Sometimes, Ubuntu does notify me of new packages that are available for installation and will ask me for permission to install these new packages. After installing these new packages, I have encountered the same error messages in your question during sudo apt update. To avoid the error, I just redo the procedure as mentioned above. Hope the developers can quickly fix this bug.
  2. I have come across advice to remove files fwupd.xml and 50appstream. However, I noticed that these files contained instructions to serve certain purposes. Hence, my fix procedure did not remove those files. If you want to remove them, I suggest you make a backup of them first.

After experiencing the same update issues I built a short-term solution that helps to mend the situation until developers adjust the syntax errors in the problematic XML file.

Proposed Short-Term Solution: bugfix.sh

#! /bin/bash
# bugfix.sh
#   Temporary fix for Ubuntu firmware update issues
#   Created by h8rt3rmin8r on 20180804
#   File location:  /var/cache/app-info/xmls/fwupd.xml
#   Line number:    265

SRC_STRING=$(sudo cat /var/cache/app-info/xmls/fwupd.xml)

touch /dev/shm/bugfix.xml
echo ${SRC_STRING/$OLD_SUBSTRING/$NEW_SUBSTRING} > /dev/shm/bugfix.xml

sudo mv /dev/shm/bugfix.xml /var/cache/app-info/xmls/fwupd.xml

Instructions On Using bugfix.sh:

To run bugfix.sh, simply copy the code above into a new file (using a text editor like gedit) and save that file as "bugfix.sh" in a convenient location.

While located in the same directory as the bugfix.sh script, enable script execution with the following command: sudo chmod +x bugfix.sh

Run the bugfix script with the command: ./bugfix.sh

Additional Notes:

Running this script will temporarily solve the problem at hand. If the error in question pops up again at a later date then just run the script again.

For easy access you could even store this script in /usr/local/bin so you can call it directly from the terminal with bugfix.sh. Then, as long as the bug is around, you can call bugfix.sh before running sudo apt-get update && sudo apt-get -y dist-upgrade.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.