PIL: "ValueError: Images do not match"

[jajjaja]

I'm trying to write a script which selects part of a given image and tiles it in one of a variety of ways. For this, I'm using pillow (archlinux's packages of python 3.6.4 and python-pillow 4.3.0, which provides PIL). For the part of the script in question, I'm trying to paste one image, with a mask, into another image. Throughout my script, I have done this multiple times with no issues. However, this particular time I get a ValueError. After searching on the Internet, I've checked the source and destination image modes (both RGB) and sizes (source 92x78, destination 92x92). I cannot figure out the difference between this and the successful times.

The (cut down) code:

from PIL import Image, ImageDraw

# Provided rather than calculated, for simplicity
fapo = 92.38795325112868
width = 76
apo = 92
x = 57
y = 537

hv_mask = Image.new('1', (apo, apo))
draw = ImageDraw.Draw(hv_mask)
draw.polygon([(0, round(fapo/2)), (apo, round((apo-width)/2)),
   (apo, apo-round((apo-width)/2))],fill=255)
del draw

pic = Image.open('testimage.png') # pic.size = (988, 800)
pic_crop = pic.crop((x, y, x+apo, y+apo))

temp = pic_crop.rotate(45, expand=1)
temp2 = temp.crop((0, round((temp.size[1]-width)/2), apo,
   width+round((temp.size[1]-width)/2)))
temp3 = Image.new('RGB', (apo, apo))
temp3.paste(temp2, mask=hv_mask, box=(0,0))

Error:
Traceback (most recent call last):
  File "Untitled2.py", line 23, in <module>
    temp3.paste(temp2, mask=hv_mask, box=(0,0))
  File "/usr/lib/python3.6/site-packages/PIL/Image.py", line 1402, in paste
    self.im.paste(im, box, mask.im)
ValueError: images do not match