Icedove 24 not starting due to calendar extension

After upgrading my Debian testing yesterday, I had the bad surprise to see that I couldn't read my emails anymore. I'm using Icedove (aka the unbranded Thunderbird available in Debian) and the software couldn't start anymore.

After a bit of searching, the solution happens to be quite simple. I've summarized the information I found here, in the hope that it may save time for others...

The cause : incompatibility with the Lightning calendar extension

Investigating the issue, I tried to launch Icedove from the command line :

$ icedove
 [...]
 icedove: relocation error: /home/pierre/.icedove/my_profile_dir/
 extensions/{e2fda1a4-762b-4020-b5ad-a41df1933103}/components/
 Linux_x86_64-gcc3/libcalbasecomps.so: 
 symbol _ZN2js13CheckedUnwrapEP8JSObjectb,
 version xul24 not defined in file libxul.so with link time reference

Searching the web, this bug was in fact reported a few months ago and is due to me using the Lightning calendar extension from Mozilla.

Debian Bug Tracker: icedove: libxul.so incompatible with some external addons (#730450, #724688)

 One message by Carsten Schoenert points specifically to the incompatibility :

if you using lightning from Mozilla this issue is normal. The symbol tables are incompatible between Icedove/libxul and upstream lightning. Please use iceowl-extension instead. The lightning package wan't work with the Icedove packages.

And the solution seems to be : use the iceowl extension instead.

But one question remains: how to fix my email client ? How can I remove the incompatible Lightning extension if icedove doesn't start ?

The solution : removing the extension using "Safe Mode"

It happens that removing this extension was easy enough by launching icedove in Safe Mode, which disables all extensions. I had never used it, but it is easy to do from the command line :

$ icedove -safe-mode

Then, I could simply remove the Lightning extension using the regular add-ons management tab.

Now, restarting Icedove "normally", it just works!

Going forward

I'll still have to investigate the replacement solution of using iceowl extension. But since I haven't been using the Lightning calendar much for some time, I'll probably leave it like that...

Author: pierre

assistant professor in Electrical Engineering & Control View all posts by pierre