undefined reference to `operator<<(std::ostream&, gl::GLenum const&)'

[damien-lloyd]

I'm getting these two linker errors under Ubuntu 16.04 64-bit:

• undefined reference to `operator<<(std::ostream&, gl::GLenum const&)'
• undefined reference to `operator+(gl::GLenum const&, unsigned int)'

Previously, under Ubuntu 15.10 64-bit I didn't get none of these linker error messages and I was using glbinding for my projects. In Ubuntu 15.10 I compiled glbinding myself using cmake. Now, for Ubuntu 16.04 I've used the supplied PPA and installed glbinding that way.

What's going on. How do I resolve these two linker errors? Is there anything I can do to help resolve them if it's a problem on your side?

Regards,

[scheibel]

We actually didn't test glbinding on Ubuntu 16.04 by ourselves. Thanks for reporting, we will investigate this issue.
I suppose we missed some code units to adhere to the argument dependend lookup (koenig lookup).

[damien-lloyd]

In the meantime I will add your PPA to my list of repositories on Ubuntu. When an update is released which fixes these issues then I'm happy to install glbindings again. At the moment, I can't work on my projects since they rely on glbindings.

[scheibel]

From your text I take our package from the PPA is working but a local compile / link on your system doesn't work?
Do you use a special compiler?

[sbusch42]

I think it's the other way around, he's using the package from the PPA

[damien-lloyd]

Yeh, I'm using the package from your PPA. That package is the one causing the linker errors. It may compile fine, but tthere may be functions that haven't been given the proper implementations.

[scheibel]

We tried to reproduce your linker error on our machines.

We used a fresh install of Ubuntu 16.04 with the default compiler and installed glbinding from our PPA.
After that, we set up a local copy of globjects (https://github.com/cginternals/globjects) and added the use of the two signatures from your bug report. Everything compiles and links as expected.

Do you have a compiling code snippet or file that we can use to reproduce this error?
Does this error occur when you use a manual build of glbinding instead of an install from the PPA?

[damien-lloyd]

I don't have globjects installed: is that a dependency I have to install? I'm using GCC 5.3 with the multilib library also installed. The thing is I can't give a compiling code snippet because I have used your library in my own library which is in itself linked to another executable. On Ubuntu 15.10 when I used glbinding 1.1 the library and executable worked just fine, but now I think something's changed. What is globjects if I may ask? :-)

[scheibel]

No, globjects is an "example project" we used to test the linking of glbinding instead of your project (which, at the moment, we don't have access to).

[sbusch42]

globjects is an object-oriented wrapper for OpenGL, based on glbinding. You don't need it, we just used that as a test to compile some project against glbinding.

In order to debug this any further, we really need an example code from you that demonstrates the problem. Make a small test case that does not include your whole project and see if you can reproduce the error within that small test project (in that process maybe you even find out that some combination with your other dependencies causes the problem).

Otherwise we can only say: it works on our machines and we can't reproduce the bug.

[damien-lloyd]

I'm currently trying to use your library under the Eclipse IDE; I realised that this IDE is currently experiencing major issues under Ubuntu 16.04, because if I use another IDE like Qt Creator then your library compiles and links fine. It's probably because I'm using settings that were from Ubuntu 15.10 (when I compiled your library on my own). Unfortunately Eclipse IDE is preventing me from changing the build settings.

May I ask which IDE you are using on Ubuntu 16.04 to test glbinding?

[scheibel]

We used standard make files without any IDE. But usually I work with Qt Creator which uses the CodeBlocks CMake Generator. Our tested IDEs are Qt Creator, Xcode and MSVC. For others like Eclipse we cannot make any statement about compatibility or issues.

[damien-lloyd]

Okay, would it be possible to build glbinding under Debian stable/testing? What are the dependencies I'd have to resolve for that to happen?

[damien-lloyd]

I resolved the issue by reverting from Ubuntu 16.04 to 14.04 and from glbinding2.0 to glbinding1.0. Everything works fine now. It's a huge rollback, but both Ubuntu 16.04 and glbinding2.0 contain elements which are preventing me from using my library. It might be a valid option to fork glbinding1.0 since the changes you've committed were not at all efficient.