Cydia Bricked iOS 8.1.0: why and how to prevent it

[APX7000]

I Jailbroke iOS 8.1.0 on a 5s and discovered something we all need to know about cydia, and how it bricked my iPhone 5s.

Quick background;
*DFU restore to virgin iOS 8.1.0
*Latest pangu JB (stock repos only)
*Restore via iTunes to restore iPhone

My internet was very sketchy, lots of packet loss and 14.4kpbs speeds. I went into cydia and refreshed my sources, however they never completely updated due to crappy Internet. Cydia never got finished updating the stock repos, and I closed out and shut down cydia. I power cycled my iPhone when the repos hadn't finished updating and it bricked the phone.

I thought maybe it's just a fluke, so I redid the whole phone and this time I went on LTE. After updating the repos, the phone rebooted (power cycled) fine (no brick) a dozen times.

Trying to nail down what was bricking my phone when it was powered off, I went back on wifi (crappy service) and went to update my repos. They never fully updated because of my internet. I closed and terminated cydia and rebooted and again iPhone was bricked. No tweaks were installed.

When I say "bricked" I'm talking about the phone booting up to the apple logo and not going any further.

I don't want anyone in the future to run into this problem and have to restore their phone to a non JB iOS.

So make sure when you use Cydia, make sure you let it complete the repo updates before powering down your iPhone. If you go to update the repos and they hang due to crappy internet, DO NOT power off your phone until you can get the repos properly updated.

 

[willerz2]

You can accomplish a fix for the improper repo updating by running apt-get update through SSH. Your device is also not bricked since Cydia repos write to Cydia's directory, and does not affect the bootchain, overwrite essential daemons, or radio baseband firmwares, only of which will cause a bricked device.