Program compiles, but cannot run because of missing library that exists

Question

I have an OpenGL program. I have all the include directories, and everything.

Directory Structure:

Main.cpp
Lib/
GL/
GLEW/
glm/

I compile the program by running:

g++ main.cpp -lGL -lm -lX11 -lpthread -lXi -lXrandr -ldl -I. -lglfw -Llib/ -o main -lGLEW

The error is on -lGLEW. The program compiles with no errors, but when I run ./main, it gives me this:

Error while loading shared libraries: libGLEW.so.2.2: No such file or directory.

This is confusing, as in my lib/ directory, libGLEW.so.2.2 is present, so is libGLEW.so and libGLEW.a.

Can someone please help me?

Thank you. `-Llib/` specifies a lib directory relative to the current working directory, which may not be what you expect it to be. Worth confirming. On the other hand, if lib is one of the conventional directory like /usr/lib, it should already be in the path, but also worth checking. — user4581301, Jan 10 '22 at 16:54

score 2 · Accepted Answer · edited Jan 11 '22 at 18:25

2

When running a dynamic linked executable, the linker must be able to find all the libraries it needs. It always searches

a list of fixed default paths like /lib and /usr/lib
additional paths defined by the environment variable LD_LIBRARY_PATH
any non-standard paths hard-coded in the binary by the -Wl,-rpath g++ option.

These are your options for making this non-standard library known to the runtime linker.

So either use export LD_LIBRARY_PATH=<somepath>/lib when running or use -Wl,-rpath=<somepath>/lib (with comma and without spaces) when building.

edited Jan 11 '22 at 18:25

answered Jan 10 '22 at 17:03

mmomtchev

I tried running ```export LD_LIBRARY_PATH=~/projectname/lib/``` but it didn’t work. – Samuel Jan 10 '22 at 17:51
Does `ls ~/projectname/lib/libGLEW.so.2.2` work? – mmomtchev Jan 10 '22 at 17:54
Try `export LD_LIBRARY_PATH=${HOME}/projectname/lib/` – mmomtchev Jan 10 '22 at 17:55
Try `export LD_LIBRARY_PATH=lib` which will work only if you run from the current directory - `./main` Also, did you copy correctly `rpath` - there are no spaces `-Wl,-rpath=lib` – mmomtchev Jan 10 '22 at 17:57
`-Wl` means pass the option to the linker, `-rpath` is the linker option, so `-Wl,-rpath=lib` without any space – mmomtchev Jan 10 '22 at 17:59
That worked! I did not know you did not include spaces in ```-Wl,-rpath=lib```! Accepting answer! – Samuel Jan 10 '22 at 18:00

1 Answers1