set cmd {./yarrg --find-window-only --quiet}
if {[info exists ocean]} { lappend cmd --ocean $ocean }
if {[info exists pirate]} { lappend cmd --pirate $pirate }
- manyset [split [eval exec $cmd] " "] ocean pirate
+ if {[catch {
+ manyset [split [eval exec $cmd] " "] ocean pirate
+ } emsg]} {
+ puts stderr "yarrg: [string trim $emsg]"
+ puts stderr "Alternatively pass, --ocean and perhaps --pirate options to where-vessels"
+ exit 1
+ }
if {![llength $ocean] || ![llength $pirate]} {
error "$ocean $pirate ?"
}