I suggest the following changes. 'bitbake -e' is a very important debugging
aid, hence why I think it should be moved earlier. I have also seen people
being confused about the "scope" of variables, so I'll piggyback a note that
might help.

* Rename '2.3.1. Task Failures' to '2.3.1. Viewing logs from failed tasks'.

* Move '2.3.8 Variables' to 2.3.2. and rename it to '2.3.2. Viewing variable
values' (this makes it consistent with 2.3.1). Rewrite it like this to clarify
and flesh it out:

  BitBake's -e option is used to display variable values after parsing. The
  following command displays the variable values after the configuration
  (local.conf, bblayers.conf, etc.) has been parsed.
  
      $ bitbake -e
  
  The following command displays variable values after a specific recipe
  has been parsed. This includes variables from the configuration as well.
  
      $ bitbake -e recipename
  
  Note {
  Each recipe has its own private set of variables (datastore). Internally, after
  parsing the configuration, a copy of the resulting datastore is made prior to
  parsing each recipe. This implies that variables set in one recipe won't be
  visible to other recipes.
  
  Likewise, each task within a recipe gets a private datastore based on the
  recipe datastore, meaning variables set within one task won't be visible to
  other tasks.
  }
  
  In the output of bitbake -e, each variable is preceded by a description of
  how the variable got its value, including temporary values that were later
  overriden. This description also includes variable flags (varflags) set on
  the variable. This can be a very handy debugging aid.


Cheers,
Ulf