get debug info

[Max Ischenko <max@...>]

I have the following piece of code:

local handler = function(errstr)
	Log(LOG_ALERT, errstr)
end
local code, msg = call(dispatch_command, 
	{commands, cmd}, 'x', handler)


When error occurs I get output like this:
attempt to index field `user' (a nil value)


Can I retrieve in what chunk (file) and in what line did error occurs?

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