Exit Reasons （备查）

9.4 Exit Reasons

When a run-time error occurs, that is an exception of class error, the exit reason is a tuple {Reason,Stack}. Reason is a term indicating the type of error:
Exit Reasons. Reason Type of error
badarg Bad argument. The argument is of wrong data type, or is otherwise badly formed.
badarith Bad argument in an arithmetic expression.
{badmatch,V} Evaluation of a match expression failed. The value V did not match.
function_clause No matching function clause is found when evaluating a function call.
{case_clause,V} No matching branch is found when evaluating a case expression. The value V did not match.
if_clause No true branch is found when evaluating an if expression.
{try_clause,V} No matching branch is found when evaluating the of-section of a try expression. The value V did not match.
undef The function cannot be found when evaluating a function call.
{badfun,F} There is something wrong with a fun F.
{badarity,F} A fun is applied to the wrong number of arguments. F describes the fun and the arguments.
timeout_value The timeout value in a receive..after expression is evaluated to something else than an integer or infinity.
noproc Trying to link to a non-existing process.
{nocatch,V} Trying to evaluate a throw outside a catch. V is the thrown term.
system_limit A system limit has been reached. See Efficiency Guide for information about system limits.

Stack is the stack of function calls being evaluated when the error occurred, given as a list of tuples {Module,Name,Arity} with the most recent function call first. The most recent function call tuple may in some cases be {Module,Name,[Arg]}.