It's heartwarming to see that the spirit behind Azureus is still alive. SWT might not be what the Duke himself wants in a Java GUI framework, but it's practical and I remember the "chunks bar" in the Azureus GUI fondly. It'll enjoy firing up BiglyBT after all these years. Using a largely memory safe language makes a lot of sense for P2P software.
Potentially worth pointing out that Go is memory safe only when single threaded (races can corrupt memory), and this kind of application is very likely to use multiple threads.
But I do also generally expect it to be safer than C++. The race detector prevents a lot of badness quite effectively because it's so widely used.
Go is safe from the perspective of RCEs due to buffer overflow, which is what matters here. Happy to be enlightened otherwise, but "I broke your (poorly implemented, non-idiomatic, please use locks or channels ffs) state machine" is a lot better than "I am the return instruction pointer now"
But it does include, I see now, exactly what I was asking for – apparently there's an actively developed fork of Azureus called BiglyBT[1].
[0] https://en.wikipedia.org/wiki/Comparison_of_BitTorrent_clien...
[1] https://github.com/BiglySoftware/BiglyBT