set chan [file tempfile]
    fconfigure $chan -encoding binary
    # \xc0\n is an invalid utf-8 sequence
    puts -nonewline $chan a\nb\nc\xc0\nd\n
    flush $chan
    seek $chan 0
    fconfigure $chan -encoding utf-8 -buffering none -eofchar {} \
	-translation lf -profile strict
	-translation auto -profile strict
} -body {
    lappend res [gets $chan]
    lappend res [gets $chan]
    set status [catch {gets $chan} cres copts]
    lappend res $status $cres
    chan configure $chan -profile tcl8 
    lappend res [gets $chan]

    lappend res $status $cres
	chan configure $chan -translation binary
	set data [read $chan 4]
	foreach char [split $data {}] {
		scan $char %c ord
		lappend res [format %x $ord]
	}
    fconfigure $chan -encoding utf-8 -profile strict
    fconfigure $chan -encoding utf-8 -profile strict -translation auto
	lappend res [gets $chan]
	lappend res [gets $chan]
    return $res
} -cleanup {
    close $chan
} -match glob -result {hello AB 1 {error reading "*": invalid or incomplete multibyte or wide character}\
    1 {error reading "*": invalid or incomplete multibyte or wide character} 43 44 c0 40 EF GHI}