Comment 63 for bug 1959747

I tried to narrow this down a bit and made tests with several versions including beta releases. For me the problem starts when switching from

**88.0b3** (snappy, fast)
to
**89.0b1** (slow, high cpu usage)

I was trying to build a version for all the commits (revisions in mecurial?) in between to narrow it down further but was only successful for the latest 115 version so far. I'll keep trying, though. If someone could confirm, that the "laggyness" was introduced in between those versions, this would already be quite helpful. Archived releases can be found here: https://archive.mozilla.org/pub/thunderbird/releases/

And if someone is more familiar with building Thunderbird and mercurial (hg) version control, maybe he/she can help out building the revisions in between those releases?