vctrs internal error caused by apparent collapse package bug

[kendonB]

library(tidyverse)
library(collapse)
no_rows_tibble <- tibble::tibble(var_1 = character(), var_2 = numeric())
tmp <- no_rows_tibble |>
  collapse::fgroup_by(var_1) |>
  collapse::fsummarise(var_2 = sum(var_2))
bind_rows(tmp, tmp)
#> Error in `vec_rbind()`:
#> ! Unexpected `NULL`.
#> ℹ In file 'slice.c' at line 322.
#> ℹ This is an internal error that was detected in the vctrs package.
#>   Please report it at <https://github.com/r-lib/vctrs/issues> with a reprex (<https://tidyverse.org/help/>) and the full backtrace.

^{Created on 2025-04-23 with reprex v2.1.1}

[DavisVaughan]

Thanks, this looks like a collapse bug to me. The generated NULL column is invalid as part of a data frame.

library(tidyverse)
library(collapse)

no_rows_tibble <- tibble::tibble(var_1 = character(), var_2 = numeric())
tmp <- no_rows_tibble |>
  collapse::fgroup_by(var_1) |>
  collapse::fsummarise(var_2 = sum(var_2))

# Looks like a collapse bug. `var_2` should be `numeric()` not `NULL`.
# This is an invalid data frame.
unclass(tmp)
#> $var_1
#> character(0)
#> 
#> $var_2
#> NULL
#> 
#> attr(,"row.names")
#> integer(0)

^{Created on 2025-04-23 with reprex v2.1.1}