Cannot update, cannot do fresh install. appstreamcli at 100% cpu

[The Cog]

I am trying to install Xubuntu 16.04 32-bit but am unable to do so. The installer is stuck on "Retrieving file 48 of 48" and top shows appstreamcli stuck at 100% CPU.

So then I tried to install without downloading updates as it went. The install worked, but a post-install apt-get update hung, again with appstreamcli stuck at 100% CPU.

So then I thought I'd try apt-get update on my main 64-bit desktop and guess what: It hangs, and top shows appstreamcli stuck at 100% CPU.

Does anyone know of a way to fix this? Obviously, reinstalling isn't going to work. It looks to me like a recent update has borked something.

[Brandon_MacEachern]

Yep, I just wiped out a hard drive to install Ubuntu 16.04 same EXACT issue.

I can install by telling it not to do updates, and turning off wifi, but then I can't run apt-get update later. It just freezes at hit 4.

[The Cog]

FIXED!

While the update/install is running, open two more terminal windows. In one terminal run the command top. In the other terminal, every time top shows appstreamcli, run the command sudo pkill appstreamcli.
Of course, you can't do that if you choose to "install" from the live installer - you have to choose to try before installing, and then use the install icon on the desktop.

[Brandon_MacEachern]

You'll still end up however without being able to update the install afterwards. The server is down.

[The Cog]

That's probably a good thing. I guess they've done that to stop it issuing updates until they can rustle up a fix.

[Brandon_MacEachern]

It's however put production here at a stand still. We can't install .deb packages because we can't even satisfy the dependencies, that we usually can.

LTS shouldn't be interrupted like this.

[The Cog]

Actually, the UK mirrors are still up.
I also tested replacing the /usr/bin/appstreamcli executable with an executable empty file, and that gets rid of all the nasty errors in apt-get update. But I don't recommend doing that.
I presume that another update soon will replace that executable with a better behaved version.

[Brandon_MacEachern]

Well if the binary itself is the problem, this should not have made it in an LTS release. Because now how do you update something required to run the updater? This is literally like a meme.

"Yo dawg I heard you like updates, so I updated your updater to update your updates".

[The Cog]

I think it's likely a combination of bad metadata and an executable that doesn't handle it well. In which case they should both be fixed, but fixing either would make the current problem go away.
But I'm guessing, I really don't know.

[Brandon_MacEachern]

Well, I'm gonna go back to drinking my Scotch, tell my boss stuff's broke, and it ain't my fault. lol