Printing barnumber 1 (oh no, not again)

[Johan Vromans]

I have the following snippet:

    s1*6/8 |%0
    \set Score.currentBarNumber = #1
    s1*1/8 s1*1/2 g8\p  |%1
    g4 g8 g4 g8  |%2
    a8 a8 a8~ a4 e8  |%3

I want the bar number "1" to show at the second measure. I've tried all
the tricks from the snippet repo but didn't succeed. E.g., this prints
bar number "2" but not "1":

    \override Score.BarNumber #'break-visibility = #(lambda (barnum) #t)
    s1*6/8              |%1
    \set Score.currentBarNumber = #1
    s1*1/8 s1*1/2 g8\p  |%1
    g4 g8 g4 g8         |%2
    \revert Score.BarNumber #'break-visibility 
    a8 a8 a8~ a4 e8     |%3

What trick did I miss?

-- Johan