Warning when producing `NaN` with `distinctiveness_stack()` about funrar HOT 1 CLOSED

library(funrar)

trait_df = data.frame(tr1 = c("A", "A", "B", "B"), tr2 = c(rep(0, 3), 1),
                      tr3 = seq(4, 16, 4))

rownames(trait_df) = letters[1:4]

# Distance Matrix
dist_mat = compute_dist_matrix(trait_df)

small_mat = matrix(c(1, 0, 0, 1), nrow = 2)
colnames(small_mat) = letters[1:2]
rownames(small_mat) = c("s1", "s2")

small_df = matrix_to_stack(small_mat)

# Warning
distinctiveness(small_mat, dist_mat)
#> Distance matrix bigger than site-species matrix
#> Taking subset of distance matrix
#> Warning in distinctiveness(small_mat, dist_mat): Some communities had a single species in them
#> Computed value assigned to 'NaN'
#>      a   b
#> s1 NaN  NA
#> s2  NA NaN

# No warning + computes distinctiveness for absent species
distinctiveness_stack(small_df, "col", "row", "value", dist_mat)
#> More species in distance matrix than in community data.frame
#> Taking subset of distance matrix
#>   col row value        Di
#> 1   a  s1     1       NaN
#> 2   b  s1     0 0.1111111
#> 3   a  s2     0 0.1111111
#> 4   b  s2     1       NaN