Has anyone seen this error before:

[ERROR] Address `//` from `--changed-since` has no name part, but it's necessary because the path is the build root.

I'm getting this from my pre-commits presumably because I changed either pants.toml or the root BUILD file

I can reproduce this with a target at the root without a name, something like

run_shell_command(command="echo 'hello'")

. Do you have a target without a name?

I think you're right, I had a jvm_artifact rule with no name