HOWTO: Pair a new device for the old Firefox Sync service in Firefox 30

I got into a public fight with IceWeasel/Firefox 30 and the Mozilla sync service on pump.io last month, and was meaning to publish my “fix”… but it was so hacky, I don’t know which part of it actually worked. But, since it’s somewhat time-sensitive during this sync service transition, I figure it’s better to share this incomplete hack than to not.

The Problem: Can’t Pair New Devices in Firefox/IceWeasel 30 Using the old Firefox Sync Service

I recently switched my ThinkPad X60 from Ubuntu to Debian testing. When I tried to set up IceWeasel 30 with the Mozilla sync service, it started prompting me about creating a Firefox account — something I have absolutely no interest in doing (in fact, I was planning on moving my Firefox sync to off Mozilla’s servers to ownCloud).

I discovered that, while previously paired devies would still be able to sync using Mozilla’s old sync service for a limited time, as of Firefox/IceWeasel 30, it no longer supports pairing new devices to the old sync service.

This made me really angry. If I’d set up sync and paired the device before “upgrading” to IceWeasel/Firefox 30, I’d be syncing no problem, but Firefox/IceWeasel 30 refused to allow this. It was an infuriating combination of what felt like an anti-feature, and pressure from Mozilla to sign up for a new sync service that seems worse on the privacy front (e.g. no server-side encryption, and self-hosting is experimental now because you’d also have to self-host the Accounts service…).

The Solution: Tricking IceWeasel/Firefox by editing prefs.js

Technically, this wasn’t a new device. I’d already had my X60 Firefox set up to sync before I switched from Ubuntu to Debian. So, I managed to trick IceWeasel into letting me sync again.

This was pretty reckless (but stakes very low — brand new IceWeasel profile) and I’m not sure exactly what worked and use these instructions at your own risk, etc etc.:

• I copied the weave folder from inside my old Ubuntu Firefox profile (not sure if that mattered), plus all of the lines in prefs.js for settings that started with “services.sync.*” (this definitely mattered)
• I tried manually editing the preferences (resetting timestamps to zero, etc.), but what ended up happening is that when I opened IceWeasel with those lines just copy-pasted in from my Firefox profile in my old Ubuntu install that I’m no longer using, it gave me the “Pair a new Device” option the first time I accessed Sync settings!!
• It would disappear and not come back if I cancelled pairing, but I just tried closing IceWeasel, copying/pasting those services.sync.* lines into prefs.js again, and then I successfully paired IceWeasel 30 by doing it the first time it appeared.
• I could see “tabs from my other computers” now, but my bookmarks clearly weren’t there, so I shut IceWeasel down, and changed the value of all the services.sync.*.lastSync and services.sync.*.lastSyncLocal and a couple other similar timestamps, setting them to 0 from their prior values. Then, re-opened IceWeasel, ran the sync manually, and my bookmarks started appearing! Since then, it seems everything has been working fine

I think it was something in copying the services.sync* settings that allowed the Pair a New Device screen to work the first time I reopened IceWeasel. Then, after pairing, resetting the timestamps to 0 on the services.sync.*.lastSync* settings caused IceWeasel to download everything again anew.

YMMV. I’m not sure how much my of success depended on being able to hijack an existing client sync ID from a device that was previously configured but no longer being used (i.e. my former Ubuntu Firefox profile on my X60 that I was replacing with Debian IceWeasel). And these steps are vague and unspecific because I’m not really sure what precisely worked or what may be unwise for you to try if you don’t know what you’re doing… but feel free to contact me if you want more specifics on my set up and experience and I may be able to help.

At the very least, this will allow me to continue using the old sync service for now, until I figure out what my options are re: self-hosting, ownCloud, Mozilla’s new Firefox Accounts-based sync service, etc.