parse error when using a readr column specification for day

[hhh71050]

read_delim(I("d1\nJanuary 1, 2010"), delim = "|", col_types = cols(d1 = col_date("%B %e, %Y"))) # "%e" not work, but a "%d" works while our documentation says: Day: "%d" (2 digits), "%e" (optional leading space)