Scale disappears when scale breaks are reversed

[willgearty]

When the breaks in a scale are in the reverse order as expected by the axis, the scale no longer appears:

library(phytools)
library(ggtree)
library(paleotree)
data(RaiaCopesRule)
ggtree(ceratopsianTreeRaia, position = position_nudge(x = -ceratopsianTreeRaia$root.time)) +
  coord_geo(xlim = c(-163.5,-66), ylim = c(-2,Ntip(ceratopsianTreeRaia)), pos = list("bottom", "bottom"),
            skip = c("Paleocene", "Middle Jurassic"), dat = list("epochs", "periods"), abbrv = FALSE,
            size = list(4,5), neg = TRUE, center_end_labels = TRUE) +
  scale_x_continuous(breaks = -epochs$max_age, labels = epochs$max_age) +
  theme_tree2()

But the following works:

ggtree(ceratopsianTreeRaia, position = position_nudge(x = -ceratopsianTreeRaia$root.time)) +
  coord_geo(xlim = c(-163.5,-66), ylim = c(-2,Ntip(ceratopsianTreeRaia)), pos = list("bottom", "bottom"),
            skip = c("Paleocene", "Middle Jurassic"), dat = list("epochs", "periods"), abbrv = FALSE,
            size = list(4,5), neg = TRUE, center_end_labels = TRUE) +
  scale_x_continuous(breaks = -rev(epochs$max_age), labels = rev(epochs$max_age)) +
  theme_tree2()