Maxima code chunk with plot function: `png::readPNG(): file is not a PNG`

[rcst]

This is a race condition: Maxima returns that file path of an image/ plot that isn't yet rendered. The subsequent R code then wants to read and include that image and throws an error. Can not be reproduced reliably, since it depends on the system

[rcst]

The error was discovered by using the blogdown package. Although, the current version of rim doesn't signal an error when the file cannot be found. It's possible, that the file is still in the process of being written, while tried to be accessed.