Update: This solution doesn’t really work. Prism doesn’t start up without a network. So if you are offline, you don’t get to see anything. If you are online (connected to a network) though it works. I will update this post if I find a solution.
Here are the instructions to get Gmail Offline working with Prism on a 64 bit installation of Ubuntu 9.04. I am assuming you have already installed the package prism-google-mail. If not, go to Synaptic Package Manager and install it.
1. Download the 64 bit version of Google Gears found here. (There are 3 links; I used the last one : gears-linux-opt-05210.xpi). Download it with another browser like Opera, so that the install dialog does not pop up.
2. Open the downloaded XPI file with the Archive Manager (File roller). (It’s just a matter of right clicking and extract. )
3. Edit the install.rdf fil. Search for code that looks like :
<em:targetApplication>
<Description>
<em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
<em:minVersion>1.5</em:minVersion>
<em:maxVersion>3.0.*</em:maxVersion>
</Description>
</em:targetApplication>
and replace it with this :
<em:targetApplication>
<Description>
<em:id>prism@developer.mozilla.org</em:id>
<em:minVersion>0.1.*</em:minVersion>
<em:maxVersion>10.0.*</em:maxVersion>
</Description>
</em:targetApplication>
4. Save the file. Archive Manager will asking you whether you want to update the archive. Say Yes.
5. Open Prism – Google Mail and on the bottom right corner click the Settings button and navigate to Tools > Addons.
6. Drag and drop the modified XPI file into the Addons window.
7. That’s it.
I have combined instructions from here and here to create this post.
Finally! Thank you.
Hey jorn.. I forgot to update the post. This solution doesn’t work. It appears to work but when you are actually offline you can’t launch Gmail in Prism.
Sorry for the late update.
The latest version of Gears, 0.5.30.0 contains its own loader stub that detects which release of Firefox you’re using and then chooses the appropriate module. (At least, that’s what it does on OS X.) This fails when it gets Prism’s version number (eg, 1.0) instead of the 3.0 or 3.5 that it expects.
The workaround is simple enough, although a bit of an ugly hack.