Bug#930231: Missing libdazzle dep impacting epiphany-browser adblock?

[Simon McVittie]

Control: tags -1 + moreinfo

On Sat, 08 Jun 2019 at 21:23:09 -0400, asmegir wrote:
> As an update here I stumbled across an apparent fix while configuring
> neomutt to use epiphany-browser to view a local copy of an HTML email. I
> noticed that this process issued a complaint about a missing libdazzle.
> I installed libdazzle-1.0-0 and now it seems adblock is working
> properly.

This is not meant to be necessary. epiphany-browser contains a bundled
copy of a different version of libdazzle and is meant to use it
preferentially. You seem to be experiencing some bug that results
in that version not being loaded - we've seen this before on #927731.

The system copy of libdazzle is older than the one epiphany-browser is
meant to be using (if the system copy was new enough, we would have used
it, with a proper dependency), so the workaround of installing a system
libdazzle-1.0-0 is not necessarily going to work - we need to solve the
bug instead.

Unfortunately, I can't reproduce the bug myself, which
makes it impossible for me to diagnose or fix it. I have
ad blocking enabled, and my epiphany-browser correctly loads
/usr/lib/x86_64-linux-gnu/epiphany-browser/libdazzle-1.0.so.0, and seems
to be blocking ads as expected (tested with slashdot.org, where I see
more ads when I disable ad blocking). However, my epiphany-browser also
doesn't seem to load libephywebextension.so at all, and I don't know
which configuration or features would make it do that.

Please try this:

* Remove libdazzle-1.0-0 (if nothing else depends on it)
* Install the strace package
* Close all epiphany-browser windows and tabs except one
* Close the browser completely
* Run: "strace -efile epiphany-browser > strace.log 2>&1"
* When the browser has finished loading, close it
* Send the log (or at least 50 lines around each mention of libdazzle)
  to this bug

You can censor the log if there is anything sensitive or confidential
in it, as long as you make it obvious where you did.

It would also be interesting if you could try creating a temporary new
user account on the same machine, and running epiphany-browser from there,
again with ad blocking enabled. If you get different results, please send
the same strace log from that user account: the differences between them
might give us some clues.

Thanks,
    smcv