XLA_FLAGS for dumping not returning HLO

[christianjgreen]

I am trying to analyze the optimized HLO outputs for a few Nx functions using this flag in a live book: system_env: %{"XLA_FLAGS" => "--xla_dump_to=/tmp/hlo"}, however no dumps are generated.

If there's another preferred way to get the optimized dumps for a function, I'd love to know how the core devs originally checked the output graphs.

Thanks for any help/tips!