unnest_longer(): do not know how to convert 'value' to class “Date”

[selesnow]

Hi, i try unnesting date column by unnest_longer(), and get do not know how to convert 'value' to class “Date”, but its works when i use unnest()`

data example

# package
library(dplyr)
library(tidyr)
library(lubridate)

# test frame
df <- data.frame(
  transaction_id = c("1", "2"),
  trade_date = as.Date(c("2019-07-01", "2019-08-01")),
  start = as.Date(c("2019-08-01", "2019-12-01")),
  end = as.Date(c("2019-10-31", "2020-02-28")),
  price = c(5, 6),
  currency = c("CAD", "CAD"),
  volume = c(10000, 5000)
)

unnest_longer example

# unnest_longer
df %>%
  group_by(transaction_id) %>% 
  mutate(start=list(seq(start, end, "months"))) %>% 
  unnest_longer(col=start)

Result:

Error in as.Date.default(value) : 
  do not know how to convert 'value' to class “Date”

unnest example

# unnest
df %>%
  group_by(transaction_id) %>% 
  mutate(start=list(seq(start, end, "months"))) %>% 
  unnest(col=start)

Result: OK

It`is normal behavior?

sessionInfo()

R version 4.0.3 (2020-10-10)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)

Matrix products: default

locale:
[1] LC_COLLATE=Russian_Ukraine.1251  LC_CTYPE=Russian_Ukraine.1251    LC_MONETARY=Russian_Ukraine.1251 LC_NUMERIC=C                    
[5] LC_TIME=Russian_Ukraine.1251    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] lubridate_1.7.9          stringr_1.4.0            zoo_1.8-8                googlesheets4_0.2.0.9000 dplyr_1.0.2             
[6] tidyr_1.1.2             

loaded via a namespace (and not attached):
 [1] tidyselect_1.1.0  xfun_0.18         remotes_2.2.0     purrr_0.3.4       gargle_0.5.0.9000 lattice_0.20-41   vctrs_0.3.6      
 [8] generics_0.1.0    testthat_2.3.2    usethis_1.6.3     htmltools_0.5.0   yaml_2.2.1        utf8_1.1.4        rlang_0.4.9      
[15] pkgbuild_1.1.0    pillar_1.4.7      glue_1.4.2        withr_2.3.0       sessioninfo_1.1.1 lifecycle_0.2.0   cellranger_1.1.0 
[22] devtools_2.3.2    memoise_1.1.0     evaluate_0.14     knitr_1.30        callr_3.5.1       ps_1.4.0          curl_4.3         
[29] fansi_0.4.1       Rcpp_1.0.5        openssl_1.4.3     backports_1.1.10  desc_1.2.0        pkgload_1.1.0     jsonlite_1.7.2   
[36] fs_1.5.0          googleAuthR_1.3.0 askpass_1.1       digest_0.6.27     stringi_1.5.3     processx_3.4.4    rprojroot_1.3-2  
[43] grid_4.0.3        cli_2.2.0         tools_4.0.3       magrittr_2.0.1    tibble_3.0.4      crayon_1.3.4      pkgconfig_2.0.3  
[50] ellipsis_0.3.1    prettyunits_1.1.1 googledrive_1.0.1 assertthat_0.2.1  rmarkdown_2.4     httr_1.4.2        rstudioapi_0.11  
[57] R6_2.5.0          compiler_4.0.3   

[hadley]

Somewhat more minimal reprex:

library(tidyr)

df <- tibble(start = as.list(as.Date(c("2019-08-01", "2019-12-01"))))
df %>% unnest_longer(start)
#> Error in as.Date.default(value): do not know how to convert 'value' to class "Date"

^{Created on 2021-02-17 by the reprex package (v1.0.0)}