2) Start emacs in text mode with:
emacs -nw -Q -l test.el
3) Create a few tabs with "C-x t 2"
The menu-bar is not showing after emacs starts. In addition, tabs start
to appear in two lines. Other visual artifacts (lines jumping around for
example) will become apparent after using emacs for a while.
In the real world this problem appeared because I had customized a
variable (tab-bar-select-tab-modifiers) that ran:
in its :set function.
In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.25)
of 2021-02-13 built on bastian-desktop
Repository revision: d3a399dd299bf7e811cf42950d5f8ac67f063b36
Repository branch: makepkg
Windowing system distributor 'The X.Org Foundation', version 11.0.12010000
System Description: Arch Linux
value of $LANG: en_US.UTF-8
Major mode: Article
Minor modes in effect: