in xar/xar_util.py [0:0]
def find_mksquashfs():
# Prefer these paths, if none exist fall back to user's $PATH
paths = ["/usr/sbin/mksquashfs", "/sbin/mksquashfs"]
for path in paths:
if os.path.isfile(path) and os.access(path, os.X_OK):
return path
return "mksquashfs"