@NicolasLagaillardie, sorry if I was unclear. This is due to the way that you are collecting Rust coverage reports. I would take a look at configuration options for whatever tool you are using. For example, if you are using grcov, I would take a look at their documentation to see if there is a configuration option or caveat.
It is the coverage tool, that is currently marking that line as uncovered, thus, that is what we are displaying on our UI.