> So, when you say you installed 1.3.5, and then installed 1.4; did you un-install 1.3.5 before you installed 1.4?

yes, I uninstalled 1.3.5 before installing 1.4 - and 1.4 did not worked

then I uninstalled 1.4 and re-install 1.3.5 and 1.3.5 didn't work this time

so the only time it worked was at the first install (of 1.3.5)

> I don't know Manjaro, or how it sets things up, but when I see a path like "/run/media" I assume it is a path to a removable medium 

it's a path to a NTFS partition on the same disk with my / and /home partitions for Linux.

I was a Windows user until recently so the biggest partition is NTFS.

I wanted to have FLTK there so I could use it from Windows too (and build in a different subfolder).

If it's something wrong with that, I could increase the size /home to have a path like you said

> Does VScode generate your Makefile for you? If not, then setting the paths in VScode is unlikely to make them visible in the Makefile.

I created the Makefile after you example

here it is:

(I'll check also how VSCode can create the Makefile)

Thanks for taking the time!

################ template makefile ##############

# We don't know what compiler to use to build fltk on this machine - but fltk-config does...

CXX = $(shell fltk-config --cxx)

# Set the flags for compiler: fltk-config knows the basic settings, then we can add our own...

CXXFLAGS = $(shell fltk-config --cxxflags) -w -Wall -std=c++14 -O3 -I/other/include/paths... -I/run/media/repos/fltk-1.4.x/ -I/run/media/repos/fltk-1.4.x/build/ -I/run/media/repos/fltk-1.4.x/build/lib/

# We don't know what libraries to link with: fltk-config does...

LINKFLTK = $(shell fltk-config --ldstaticflags)

LINKFLTK_GL = $(shell fltk-config --use-gl --ldstaticflags)

LINKFLTK_IMG = $(shell fltk-config --use-images --ldstaticflags)

# Define what your target application is called

all: 13.12_circle.bin

# Define how to build the various object files...

Graph.o: Graph.cpp Graph.H

$(CXX) -c $< $(CXXFLAGS)

Window.o: Window.cpp Window.H

$(CXX) -c $< $(CXXFLAGS)

GUI.o: GUI.cpp GUI.H

$(CXX) -c $< $(CXXFLAGS)

Simple_window.o: Simple_window.cpp Simple_window.H

$(CXX) -c $< $(CXXFLAGS)

13.12_circle.o: 13.12_circle.cpp

$(CXX) -c $< $(CXXFLAGS)

# Now define how to link the final app - let's assume it needs image and OpenGL support

13.12_circle.bin:  Graph.o Window.o GUI.o Simple_window.o 13.12_circle.o

$(CXX) -o $@ Graph.o Window.o GUI.o Simple_window.o 13.12_circle.o $(LINKFLTK) $(LINKFLTK_GL) $(LINKFLTK_IMG)

clean:

rm -rf *.o

############### end #################