list [catch {read $chan 1} msg] $msg
} -cleanup {
    close $chan
    unset msg chan
} -match glob -result {1 {error reading "*":\
    invalid or incomplete multibyte or wide character}}

test io-75.9 {unrepresentable character write throws error in strict profile} -setup {
    set fn [makeFile {} io-75.9]
    set f [open $fn w+]
    fconfigure $f -encoding iso8859-1 -profile strict
} -body {
    catch {puts -nonewline $f "A\u2022"} msg
    flush $f
    seek $f 0