I cannot install any package. It seems the command apt-get update must be run but it throws some errors:

$ sudo apt-get update
Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB]     
Hit:2 http://ve.archive.ubuntu.com/ubuntu xenial InRelease                     
Hit:3 http://ve.archive.ubuntu.com/ubuntu xenial-updates InRelease             
Hit:4 http://ve.archive.ubuntu.com/ubuntu xenial-backports InRelease           
Fetched 102 kB in 23s (4337 B/s)                                               
*** Error in `appstreamcli': double free or corruption (fasttop): 0x000000000210f4b0 ***
======= Backtrace: =========
Aborted (core dumped)
Reading package lists... Done
E: Problem executing scripts APT::Update::Post-Invoke-Success 
 'if /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; 
 then appstreamcli refresh > /dev/null; fi'
E: Sub-process returned an error code

Full terminal output.txt

  • 1
    Related bug: bugs.debian.org/cgi-bin/bugreport.cgi?bug=822317 – Elder Geek Oct 29 '17 at 23:34
  • Maybe this problem has something to do with Python (version? home folder? I don't know). I explain: I had a similar problem on Ubuntu 20, but the answers here didn't work for me. However, the problem disappeared when I realized that I had changed the symbolic link /usr/bin/python3 to /usr/bin/ph3 (yeah, laziness...) a couple of minutes before the error started to show up. When I put it back to \usr\bin\python3 both the sudo apt update and sudo apt upgrade worked well. Maybe some of the programs that are been updated/upgraded need Python. Please, check this out. I hope it helps. – Almir Campos May 9 at 23:32

This worked for me (From here, https://forum.siduction.org/index.php?topic=6174.0):

sudo apt-get purge libappstream3
| improve this answer | |
  • 6
    What about the side effects? What caused this issue? – EdParadox Aug 9 '17 at 18:20
  • 4
    @EdParadox This happened to me yesterday when updating the software in Ubuntu 16.04 immediately after installing it in VirtualBox with the command sudo apt upgrade. This answer worked for me. I was getting many other Apport error notifications at the same time. After updating Oracle VirtualBox and Oracle VirtualBox Extension Pack to the latest version these errors disappeared. I checked in /var/crash/ and verified that all of these errors were related to appstream which has libappstream3 as a dependency. – karel Aug 10 '17 at 7:38
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    @EdParadox The cause? In my case, the error just happened with no apparent reason, when running sudo apt-get update command in Terminal. The side effect? Nothing apparent besides these packages appstream gnome-software libappstream3 being removed. – clearkimura Aug 11 '17 at 7:50
  • 5
    @Lion Just did a completely fresh install of XUbuntu 16.04 here on real hardware, I got it right away; I've never had this happen before on any other Linux distro; I'd take a guess and say that there might be something wrong with the installer. – jrh Sep 30 '17 at 3:35
  • 5
    This really saved my a**. Thanks. It's strange that one dumb package would completely fubar an entire fresh install. – Cerin Mar 24 '18 at 2:40
sudo apt install --reinstall libappstream3

can fix it.

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  • 1
    this fixed this error for me. – Brock Vond Jan 11 '18 at 0:10
  • 4
    I ran apt install --reinstall libappstream* – jtlindsey Apr 15 '18 at 18:35
  • 1
    Way better solution than the accepted answer, it prevents extra packages from being removed as well (at least on KDE). – kursus Sep 3 '18 at 17:55
  • I get an error: The following packages have unmet dependencies: code : Depends: libnss3 (>= 2:3.26) but 2:3.21-1ubuntu4 is to be installed – Владимир Смирнов Sep 21 '18 at 16:34
  • If this works it would be better, agreed. As I recall.. I tried it but got some dependency error. – Max Robbertze Oct 4 '18 at 9:00

I came from this page and was redirected here, over there I cannot answer but this is actually an answer for that page. Since I had the same issue (at least same as one of the related issues, but hey I did not relate them so sorry if it is not right solution for you ) and found it quite difficult to find the right information, but in the end succeeded, I thought why not share it here. It took me 2 days evening hours to put the pieces together but this is what I did, hope it helps some of you.

I followed this procedure to clean the mess, made a backup first, just in case.

sudo apt install appstream/xenial-backports
sudo rm /etc/apt/apt.conf.d/50appstream
sudo rm /var/cache/app-info/xmls/fwupd.xml
sudo apt install --reinstall libappstream4
sudo appstreamcli refresh --force
sudo reboot

Not sure if the reboot is necessary but after reboot I did:

sudo appstreamcli refresh --force

and had no more errors.

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  • 1
    For me that did the trick - removing fwupd.xml and re-installing libappstream4. Thanks! – valiano Jul 22 '18 at 5:22
  • 1
    B4 your procedure, I backed up fwupd.xml and 50appstream. After your procedure, the errors disappeared after sudo apt update ( tested for a few reboots). I reinserted 50appstream to original location, ran sudo appstreamcli refresh --force followed by sudo apt update; no error msg. After reinserting fwupd.xml and do refresh --force and update commands, this error appeared AppStream system cache was updated, but problems were found: Metadata files have errors: /var/cache/app-info/xmls/fwupd.xml. So fwupd.xml caused error. The symbol & in line 265 is the likely cause? – Sun Bear Jul 23 '18 at 9:35
  • 1
    bugs.launchpad.net/ubuntu/+source/appstream/+bug/1644498 A fix was released in 2017/01 but in 2018/07 this same issue reappears. Think the previous bug fix is no longer working for current error? Seems to be an up trend of this error... Hope a new solution can be found. – Sun Bear Jul 23 '18 at 9:40
  • 2
    I concluded the files fwupd.xml and 50appstream should not be removed. They have a purpose. I have posted my solution here. After fixing the typo in fwupd.xml, everything works again. – Sun Bear Jul 23 '18 at 15:41
  • 1
    @Sun Bear I had this exact same problem and your solution worked for me. Thanks – Scooby-2 Aug 5 '18 at 18:45

I had this issue after upgrading from 16.04 LTS to 18.04.1 LTS. My initial error message was:

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

Here is what I did to fix it:

$ sudo rm /var/cache/app-info/xmls/fwupd.xml
$ sudo appstreamcli refresh --force

That resulted in this terminal message:

AppStream cache update completed successfully.

Then, sudo apt-get update and sudo apt-get upgrade worked perfectly.

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In my case, purging, or re-installing didn't help.

The removal of the apt.conf.d entry did however solve the issue for me.

Friday 25 August  22:17:45 AEST 2017
LSB Version:    core-9.20160110ubuntu0.2-amd64:core-9.20160110ubuntu0.2-noarch:printing-9.20160110ubuntu0.2-amd64:printing-9.20160110ubuntu0.2-noarch:security-9.20160110ubuntu0.2-amd64:security-9.20160110ubuntu0.2-noarch
    Distributor ID: Ubuntu
    Description:    Ubuntu 16.04.3 LTS
    Release:    16.04
    Codename:   xenial

I ran the following commands to get rid of the error:

sudo apt-get purge libappstream2
sudo rm /etc/apt/apt.conf.d/50appstream
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For having this:

$ sudo apt-get update
[sudo] password for XXX:           

AppStream system cache was updated, but problems were found: Metadata files have errors: /var/cache/app-info/xmls/fwupd.xml
Reading package lists... Done
E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then appstreamcli refresh-cache > /dev/null; fi'
E: Sub-process returned an error code

$ sudo appstreamcli --version
AppStream CLI tool version: 0.10.6

$ sudo appstreamcli refresh-cache --force --verbose
** (appstreamcli:15334): DEBUG: Added /usr/share/app-info/xmls to metadata search path.
** (appstreamcli:15334): DEBUG: Added /var/lib/app-info/yaml to metadata search path.
** (appstreamcli:15334): DEBUG: Added /var/cache/app-info/xmls to metadata search path.
** (appstreamcli:15334): DEBUG: Refreshing AppStream cache
** (appstreamcli:15334): DEBUG: Searching for data in: /usr/share/app-info/xmls
** (appstreamcli:15334): DEBUG: Searching for data in: /var/cache/app-info/xmls
** (appstreamcli:15334): DEBUG: Searching for data in: /var/lib/app-info/yaml
** (appstreamcli:15334): DEBUG: Reading: /usr/share/app-info/xmls/org.freedesktop.fwupd.xml
** (appstreamcli:15334): DEBUG: Reading: /var/cache/app-info/xmls/fwupd.xml
** (appstreamcli:15334): DEBUG: WARNING: Could not parse XML data: Entity: line 265: parser error : EntityRef: expecting ';'
        <checksum filename="Firmware_SF30&SN30_Pro_V1.26.dat" target="content" t

The fix is:

$ sudo -i

# cd /var/cache/app-info/xmls/

# ls -l
total 236
drwxr-xr-x 2 root root   4096 jul 27 09:56 ./
drwxr-xr-x 5 root root   4096 aug 31  2017 ../
-rw-r--r-- 1 root root 233177 jun 29 16:02 fwupd.xml

# sed < fwupd.xml  -rne 's/Firmware_SF30\&SN30_Pro_V1.26.dat/Firmware_SF30\&SN30_Pro_V1.26.dat/gp'
        <checksum filename="Firmware_SF30&SN30_Pro_V1.26.dat" target="content" type="sha1">3ef2bdee8aca2a45b9f53b4d4cce9722523f57f8</checksum>

# sed fwupd.xml -i_BACKUP -re 's/Firmware_SF30\&SN30_Pro_V1.26.dat/Firmware_SF30\&SN30_Pro_V1.26.dat/gp'

# ls -l
total 464
drwxr-xr-x 2 root root   4096 jul 27 09:57 ./
drwxr-xr-x 5 root root   4096 aug 31  2017 ../
-rw-r--r-- 1 root root 233328 jul 27 09:57 fwupd.xml
-rw-r--r-- 1 root root 233177 jun 29 16:02 fwupd.xml_BACKUP

# rm fwupd.xml_BACKUP

# apt-get update
Hit:1 http://se.archive.ubuntu.com/ubuntu xenial InRelease
Fetched 491 kB in 0s (715 kB/s)                    
Reading package lists... Done

# exit



| improve this answer | |

A working solution in 18.04.1 is to install appstream and libappstream4 manually from the Cosmic repos; pick your architecture and a mirror, download, install with dpkg -i, then try appstreamcli refresh --force.

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