Problems with sudo apt update

[gumbeto]

That is the content of the file you passed to cat -- /etc/apt/sources.list -- which is one of the places where the repositories you get your software from are configured. You can read about repositories here.

Concerning the original issue, it is now being tracked in https://bugs.launchpad.net/ubuntu/xe...b/+bug/1780442

[simone93]

That is the content of the file you passed to cat -- /etc/apt/sources.list -- which is one of the places where the repositories you get your software from are configured. You can read about repositories here.

Concerning the original issue, it is now being tracked in https://bugs.launchpad.net/ubuntu/xe...b/+bug/1780442

Thanks for your reply.
Maybe they fix the problem, 10 minutes ago I gave the same command and it found a new update that seems has fix the problem:

sudo apt-get upgrade 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  linux-firmware
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 50,0 MB of archives.
After this operation, 142 kB of additional disk space will be used.
Do you want to continue? [Y/n] 
Get:1 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 linux-firmware all 1.157.20 [50,0 MB]
Fetched 50,0 MB in 14s (3.380 kB/s)                                            
(Reading database ... 360974 files and directories currently installed.)
Preparing to unpack .../linux-firmware_1.157.20_all.deb ...
Unpacking linux-firmware (1.157.20) over (1.157.19) ...
Setting up linux-firmware (1.157.20) ...
update-initramfs: Generating /boot/initrd.img-4.13.0-45-generic

I want to wait some other reboot before marked the thread as Solved.

EDIT: It's not true this doesn't fix the problem! I don't know what i've to do...

[Ivo_Wever]

The AskUbuntu issue linked earlier was wrongly closed as a duplicate: this issue is different. It is actually answered on askubuntu.com/a/1053018/28943: manually edit /var/cache/app-info/xmls/fwupd.xml to replace the & by & in the offending line (in line 265 in my version). The file simply contains an unescaped & and is thus invalid XML.

I haven't bothered to figure out where that file comes from. It's not installed directly by any package; it is probably constructed by appstream, but possibly by copying wrongly escaped XML from another file.

[gumbeto]

Unfortunately the file reverts to the original &-containing string when fwupdmgr refreshes.

[simone93]

Is there a way to make this change permanently?

Thanks for your reply!

[gumbeto]

The problem seems to be gone for me, I think a fix was released that still requires manually deleting the faulty xml file, but I was messing with my system a bit before and I am not sure if it could be related. What happens if you do

$ sudo mv /var/cache/app-info/xmls/fwupd.xml ~/fwupd.xml.bck
$ sudo fwupdmgr refresh
$ sudo appstreamcli refresh

Does it still complain?

[Tony_Bennett]

Here's my output from running the commands:

$ sudo mv /var/cache/app-info/xmls/fwupd.xml ~/fwupd.xml.bck
$ sudo fwupdmgr refresh
$ sudo appstreamcli refresh
AppStream system cache was updated, but problems were found: Metadata files have errors: /var/cache/app-info/xmls/fwupd.xml

[simone93]

Here's my output from running the commands:

$ sudo mv /var/cache/app-info/xmls/fwupd.xml ~/fwupd.xml.bck
$ sudo fwupdmgr refresh
$ sudo appstreamcli refresh
AppStream system cache was updated, but problems were found: Metadata files have errors: /var/cache/app-info/xmls/fwupd.xml

The same for me

[gumbeto]

OK, my bad, I forgot a couple of system restarts before, which totally messed up my conclusions...

So, I was able to fix this by installing libappstream-glib8 from bionic. The procedure is below. If you find yourself in one of the cases marked ABORT, just undo all the steps you did so far and run sudo apt update at the end (I don't expect that to happen though, they are just there as a safeguard).

1. save a file called (say) future.list in dir /etc/apt/sources.list.d (you'll need sudo) with the following content:
   

   deb mirror://mirrors.ubuntu.com/mirrors.txt bionic main
   deb mirror://mirrors.ubuntu.com/mirrors.txt bionic-updates main
   deb mirror://mirrors.ubuntu.com/mirrors.txt bionic-security main

2. save a file called (say) future.pref in dir [/etc/apt/preferences.d[/CODE] (you'll need sudo again) with the following content:
   

   Package: *
   Pin: release a=bionic*
   Pin-Priority: 50

3. run sudo apt update
4. run apt list -u and confirm it returns only "Listing... Done". If it returns more stuff, ABORT (see above).
5. run sudo apt install -assume-no -t=bionic libappstream-glib8. If, at this stage, apt claims that more is needed to satisfy dependencies than just replacing the old version with the new one, ABORT (see above).
6. run sudo mv /var/cache/app-info/xmls/fwupd.xml ~/fwupd.xml.bck
7. restart (I found this was required, probably to load the new shared library version and maybe restart some service. If you do try to skip it, remember to delete the xml before retrying.)
8. run sudo fwupdmgr refresh
9. run sudo appstreamcli refresh.

At this point the problem should be fixed. You can leave everything as is (perhaps deleting ~/fwupd.xml.bck if you want). When you now upgrade your packages, packages whose bionic version is installed will receive bionic upgrades, but the rest will still be on xenial.

Let me know what you find. Cheers

[sashainsydney2016]

If your problem is this error message:

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

Try:

gksudo gedit /var/cache/app-info/xmls/fwupd.xml

and look at line 265 of the file fwupd.xml.
If there you find this (note bolded):

<checksum filename="Firmware_SF30&SN30_Pro_V1.26.dat"

Change it to:

<checksum filename="Firmware_SF30&amp;SN30_Pro_V1.26.dat"

That is, replace the character "&" with the five characters "&amp;".

To be safe, you may want to make a backup of the file first, before editing it.

Further reference is here.