can't save images in general.

[nschluessel]

I'm trying to save an image to disk with the following code:

#include <matplot/matplot.h>
int main() {
    using namespace matplot;
    plot(linspace(0, 10), linspace(0, 10));
    save("img/test.png");
    return 0;
}

The weird thing is nothing happens. I don't see any error messages and I don't see a new file in /img. The only error message I get is

Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.

which I assume is not related to saving images. (I also tried to run it with Xorg just in case, which didn't work either)
I have the following project structure

and the following CMakeLists.txt

cmake_minimum_required(VERSION 3.23)
project(plotty)

set(CMAKE_CXX_STANDARD 17)
add_subdirectory(libs/matplotplusplus)

add_executable(plotty main.cpp plotter.cpp plotter.h)
target_link_libraries(plotty PUBLIC matplot)

If I remove the .png from the code above, I get the following error:

No gnuplot terminal for  files
Setting terminal to "dumb"

Other file formats (.tex, .txt, .pdf) don't seem to work either. I'm running Ubuntu 22.04.1 LTS and using CLion 2022.2.4 with CMake 3.23.2 and gnuplot 5.4 patchlevel 2.

I also copied some of the examples, which didn't work either.

EDIT: Just showing the images works fine. Just wanted to add that.
Thanks to all for your help :)

[nschluessel]

I made a silly mistake and accidentally kept looking in the wrong folder. I'm sorry for that.