Do they have a usable debugger now? My last experience was 2 years ago, and launching it even on some trivial code took over 10 seconds.
julia> @time using Debugger
0.115907 seconds (202.08 k allocations: 13.215 MiB)
julia> @time @run sin(1)
1.438537 seconds (1.85 M allocations: 90.376 MiB, 0.80% gc time)
0.8414709848078965
julia> @time @run sin(1)
0.003900 seconds (23.39 k allocations: 1.057 MiB)
0.8414709848078965