[mprovost]

In other shells, the status of the pipeline is the exit status of the last process, so in this case that would be head which exits with 0.

[aidenn0]

Not in e.g. bash with "pipefail" set. However the pipefail option in bash will choke on my previous example, hence treating a SIGPIPE the same as success in ysh.

[mprovost]

Yes well, the pipefail option configures bash to do the opposite of its usual behaviour.