The execution environment of a currently running
function, e.g. call = caller_env()
. The corresponding function
call is retrieved and mentioned in error messages as the source
of the error.
You only need to supply call
when throwing a condition from a
helper function which wouldn't be relevant to mention in the
message.
Can also be NULL
or a defused function call to
respectively not display any call or hard-code a code to display.
For more information about error calls, see Including function calls in error messages.