Bug category

• bug - compilation error
• bug - compilation warning
• bug - runtime error
• bug - runtime warning
• bug - logic error

Matplot++ Version
1.2.0

Describe the bug
I've added Matplot++ via CPM on two Ubuntu machines. I have no issues on one of them. The other, however, can not compile due to cv.h not being found which is required by the 3rd party library CImg.

In CImg.h I've tried changing the included headers to opencv2/opencv.hpp and opencv2/highgui.hpp as OpenCV 4.8.1 is installed. This, understandably, led to a bunch of errors. And removing the CImg library seems not to be a solution either as Matplot++ obviously relies on it in several ways.

Steps to Reproduce

mkdir build
cd build
cmake -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_BUILD_TYPE:STRING=Release -DCMAKE_C_COMPILER:FILEPATH=/usr/bin/gcc -DCMAKE_CXX_COMPILER:FILEPATH=/usr/bin/g++ -S<redacted_project_path> -B<redacted_project_path>/build -G "Unix Makefiles" -D ENABLE_MATPLOT=ON
make -j8

(ENABLE_MATPLOT is an option I set in my project's CMake configuration to enable/disable some components which rely on Matplot. I can build my project without Matplot++ features if I want to, so you don't need to worry about that option.)

Output

In file included from <redacted_project_path>/build/_deps/matplotplusplus-src/source/matplot/util/common.cpp:23:
<redacted_project_path>/_deps/matplotplusplus-src/source/3rd_party/cimg/CImg.h:419:10: fatal error: cv.h: No such file or directory
  419 | #include "cv.h"
      |          ^~~~~~

Platform

• cross-platform issue - linux
• cross-platform issue - windows
• cross-platform issue - macos

Environment Details:

• OS: Ubuntu
• OS Version: 20.04.6 LTS
• Compiler: GCC/G++
• Compiler version: 9.4.0

Additional context
CPM command used to add Matplot++ and the corresponding section in the specific CMake file:

    CPMAddPackage("gh:alandefreitas/matplotplusplus@1.2.0")
    target_link_libraries(${TARGET_NAME} matplot)