Show HN: Xcover, Coverage Profiling with eBPF

xcover started as a personal project, and we've already started using it internally at Chainguard to profile the test coverage of our packages. It measures function coverage, without instrumentation required at compile time, so that you can test the the binaries that you ship. It works with any ELF. This helps when you can't produce a coverage build, or when you have packages in several languages and don't want a separate coverage tool for each.

I'm also experimenting with userspace eBPF runtimes to remove the cost of the kernel traps, while also enabling unprivileged mode of xcover.

https://github.com/maxgio92/xcover/tree/userspace

Demo: https://asciinema.org/a/GyzGzTTEP63GJzAG. There's also a demo folder in the repo with a few different use cases. Happy to answer questions about how it finds functions, attaches the probes, or the userspace BPF work.

I gave a talk on this at OpenSouthCode 2026, "The Binary You Ship Is the Binary You Test." Slides are in the repo under docs/talks/opensouthcode-2026, video should be up later.