not-gloss animations don't end cleanly

[Daniel-Diaz]

I am running not-gloss animations from GHCi. Whenever I run one, and I close it, I get the following error:

freeglut ERROR: Function <glutPostRedisplay> called without first calling 'glutInit'.

After that, GHCi crashes too.

My platform is Linux(Debian) 7.

[ghorn]

I haven't been able to run at all in ghci. I always get this message:

...
...
Loading package not-gloss-0.5.0.4 ... linking ... done.
screen resolution 1920x1080
libGL error: failed to load driver: swrast
libGL error: Try again with LIBGL_DEBUG=verbose for more details.
freeglut (<interactive>):  ERROR:  Internal error <FBConfig with necessary capabilities not found> in function fgOpenWindow

As for your question, I think only freeglut supports stopping and starting with glutLeaveMainLoop (http://freeglut.sourceforge.net/docs/api.php#EventProcessing) and non-free-glut doesn't support exiting (http://www.opengl.org/discussion_boards/showthread.php/136742-Exit-Main-Loop).

I thing an upgrade from GLUT to something like GLFW is in order.

[dcw803]

Try compiling your Haskell code (not interpreting), eg. ghc --make Thingy.hs, or invoking ghci with "-lglut". We
just found the exact same error message (on Ubuntu 13.04, ghci version 7.6.2, having ensured that
the libghc-glut-dev Ubuntu package was installed first). First we found that compiling the Haskell code and
running that worked fine, then we found that the interpreter worked if we ran "ghci -lglut Thingy.hs"; don't really
understand why it worked;-(