Issue migrated from dplyr tidyverse/dplyr#1525. Updated to show the different error message produced by tibble.
BTW you're going to get a lot of issues about nibble if my auto-correct has its way.
This is handy for inspecting list-columns.
library(tibble)
x <- data_frame(a = 1:3, b = lapply(a, seq_len))
x[[3, 2]]
#> Error in .subset2(x, i): subscript out of bounds