The implementation is naive because the user has to generate exactly the
event he specified. That is, if you use this binding:
bindsym --release $mod+x exec import /tmp/latest-screenshot.png
Then it will only be triggered if you hit $mod, hit x, release x,
release $mod. It will not be triggered if you hit $mod, hit x, release
$mod, release x. The reason is that the KeyRelease event in the latter
case will not have the modifier in its flags, so it doesn’t match the
configured binding.
See also commit 0e752070ac2bed02d0858bbc450ddcee36e3b9b5, which broke
source code listings in gdb unless you cd into i3/src. This should give
us best of both :-).
e.g. pressing Mod1+x when having the following in your configfile:
bindsym Mod1+x some invalid command
will lead to an i3-nagbar instance popping up, offering you to view the
error log (which will contain parser errors from this commit on).