Why is there a space between the bars and the axis in ggplot2 bar graphs, and how do I get rid of it? - ggplot2

Question

I've been building a bar graph in R, and I noticed a problem. whenever the graph is made, it has a very small gap between the bars and the axis that causes a line of the background image to appear (Link). How can I get rid of this?
Code:
album_cover <- image_read("https://i.scdn.co/image/ab67616d0000b273922a12ba0b5a66f034dc9959")
ggplot(data=album_df, aes(x=rev(factor(track_names, track_names)), y=-1 * track_length)) +
ggtitle("Songs vs length")+
annotation_custom(rasterGrob(album_cover,
width = unit(1,"npc"),
height = unit(1,"npc")),
-Inf, Inf, -Inf, Inf)+
#geom_image(image = "https://i.scdn.co/image/ab67616d0000b273922a12ba0b5a66f034dc9959", size = Inf) +
geom_bar(stat="identity", position = "identity", color = 'NA', alpha = 0.9, width = 1, fill = 'white') +
scale_y_continuous(expand = c(0, 0), limits = c(-1 * max_track, 0)) +
scale_x_discrete(expand = c(0, 0)) +
theme(axis.title.x=element_blank(),
axis.title.y=element_blank(),
axis.text.x=element_blank(),
axis.ticks.x=element_blank()
) +
coord_flip()

Answer 1

Interesting issue. I've tried many things, including modification of many of the theme elements. It works with theme_void(), but then the issue resurfaces as you add back in the plot elements (namely the song titles on the axis, for some reason).
What finally did work is just squishing your image to be ever so slightly less than 1. In this case, just changing from 1 to 0.999 fixes the issue and you no longer have the strip of the image hanging out on the right. For this, I made up my own data, but I'm using the same image:
df <- data.frame(
track_names=paste0('Song',1:8),
track_length=c(3.5,7.5,5,3,7,10,6,7.4)
)
album_cover <- image_read2("https://i.scdn.co/image/ab67616d0000b273922a12ba0b5a66f034dc9959")
ggplot(data=df, aes(x=track_names, y=-1*track_length)) +
annotation_custom(rasterGrob(album_cover,
width=unit(0.999,'npc'), height=unit(1,'npc')),
xmin=-Inf, xmax=Inf, ymin=-Inf, ymax=Inf) +
geom_col(alpha=0.9, width=1, fill='white', color=NA) +
scale_y_continuous(expand=c(0,0)) +
scale_x_discrete(expand=c(0,0)) +
ggtitle('Songs vs Length') +
coord_flip()
Note, the same code above gives the following image below when width=unit(1, 'npc'),... in the rasterGrob() function (note the line at the right side of the image):