Can you pull a line number from a caught error?

New to Julia
1

Can you pull a line number from a caught error?
Im running multiple threads and when an error is found the Task dies, i was wondering if it is possible to get the line number and module or file from an error that has been caught?

2

stacktrace() gives you a vector of StackFrames which include the corresponding file and line number (but this probably gives you more information where the error is caught, rather than thrown)

1 Like
3

Sadly it does seem to be only where it is caught, maybe the data on where the error was is just lost

4

If you have the freedom to throw the errors yourself, you can cook up something like this:

struct MyException{T<:Exception} <: Exception
    err::T
    file::Symbol
    line::Int
end

function Base.showerror(io::IO, err::MyException)
    print(io, err.err)
end

macro myerror(err)
    return :( throw(MyException($(esc(err)),
                                $(QuoteNode(__source__.file)),
                                $(QuoteNode(__source__.line)))) )
end

function catch_error()
    try
        @myerror ErrorException("Error!")
    catch e
        if e isa MyException
            println("Caught error thrown at $(e.file):$(e.line)")
        end
    end
end

julia> catch_error()
Caught error thrown at /tmp/bar.jl:19

Line 19 is where the error is thrown.

5

BTW, there is catch_backtrace which should do exactly what you want, but you need to extract the information out of its pointers.