Fixed, thanks: https://github.com/tidyverts/feasts/commit/f7894e859fe0258122011ce5148282b121b0c0d1
library(fpp3)
#> ── Attaching packages ────────────────────────────────────────────── fpp3 0.3 ──
#> ✓ tibble 3.0.4 ✓ tsibble 0.9.3.9000
#> ✓ dplyr 1.0.2 ✓ tsibbledata 0.2.0
#> ✓ tidyr 1.1.2 ✓ feasts 0.1.5.9000
#> ✓ lubridate 1.7.9 ✓ fable 0.2.1.9000
#> ✓ ggplot2 3.3.2
#> ── Conflicts ───────────────────────────────────────────────── fpp3_conflicts ──
#> x lubridate::date() masks base::date()
#> x dplyr::filter() masks stats::filter()
#> x tsibble::interval() masks lubridate::interval()
#> x dplyr::lag() masks stats::lag()
#> summing to daily
z <- index_by(pedestrian, Date) %>%
summarise(Count2 = sum(Count))
gg_season(z, y = Count2, period = 'year')

#>summing to weekly
z2 <- index_by(pedestrian, yearweek(Date)) %>%
summarise(Count2 = sum(Count))
gg_season(z2, y = Count2, period = 'year')

Created on 2020-11-16 by the reprex package (v0.3.0)