I check in on Xonsh every once in a while. The first test I do is try and suspend a sleep into the background. This has never worked on xonsh afaict. I am excited to give Xonsh a spin, but I can't until it gets its job control story sorted out.
They are unfortunately not implementing posix correctly. Instead of using proper processes they use threads to control certain things which makes <ctrl-z> not work properly.
This would actually be possible to fix, but it's quite a bit of work.
