746 introduced support for current_exceptions (née catch_stack), which bears a backtrace keyword argument. When backtrace=false, the returned ExceptionStack's stack field should be a Vector of NamedTuples where the second (backtrace) element of each tuple is nothing. Instead the Compat implementation throws, e.g. on Julia 1.6.2:
julia> using Compat: current_exceptions
julia> try
throw(UndefVarError(:cat))
catch
current_exceptions(;backtrace=false)
end
ERROR: MethodError: no method matching getindex(::UndefVarError, ::Int64)
Stacktrace:
[1] current_exceptions(task::Task; backtrace::Bool)
@ Compat ~/pkg/Compat.jl/src/Compat.jl:1105
[2] top-level scope
@ REPL[7]:4
caused by: UndefVarError: cat not defined
Stacktrace:
[1] top-level scope
@ REPL[7]:2
The trick is that the implementation
function current_exceptions(task=current_task(); backtrace=true)
stack = Base.catch_stack(task, include_bt=backtrace)
ExceptionStack(Any[(exception=x[1],backtrace=x[2]) for x in stack])
end
passes the backtrace kwarg through to catch_stack which, when include_bt=false, emits a Vector of exceptions, rather than a Vector of two-tuples (exception-backtrace pairs). The array comprehension on the next line expects a Vector of two-tuples, though, and consequently ends up attempting to index into exceptions.
746 introduced support for
current_exceptions(néecatch_stack), which bears abacktracekeyword argument. Whenbacktrace=false, the returnedExceptionStack'sstackfield should be aVectorofNamedTuples where the second (backtrace) element of each tuple isnothing. Instead the Compat implementation throws, e.g. on Julia 1.6.2:The trick is that the implementation
passes the
backtracekwarg through tocatch_stackwhich, wheninclude_bt=false, emits aVectorof exceptions, rather than aVectorof two-tuples (exception-backtrace pairs). The array comprehension on the next line expects aVectorof two-tuples, though, and consequently ends up attempting to index into exceptions.Patch inbound :).