There's work happening to make DevTools console directly connect to the worker thread so we don't have to rely on the cloning mechanism we currently have.
Initial patch for that will be done in Bug 1592584, where we'll check the value of the dom.worker.console.dispatch_events_to_main_thread pref, and connect to worker thread if it's false.

The end game would be to completely remove this pref, alongside with the whole cloning mechanism.
There are some work to be done before we can get to that point, and those bugs should be added as blockers for this bug.

Is this by any chance close to completion? If yes, I won't bother with supporting structured cloning of Error stacks in the console in bug 1774866.

(In reply to Tom Schuster [:evilpie] from comment #2)

Is this by any chance close to completion? If yes, I won't bother with supporting structured cloning of Error stacks in the console in bug 1774866.

Maybe? I can't remember if we were missing more.
As a first step, we could make https://searchfox.org/mozilla-central/source/modules/libpref/init/StaticPrefList.yaml#4335 enabled on Nightly

I tried setting the pref to false on Nightly and there are quite some failures: https://treeherder.mozilla.org/jobs?repo=try&revision=eeb754f0a5c362808fd658f1e250c8c873b655e7

Maybe these are only tests not expecting messages; I should go over those to figure this out