Created attachment 410902 [details, diff] Move the definition of the offending template to the header. The build fails with: ---- cd /home/portage/dev-games/ogre-1.9.0-r1/work/ogre-1.9.0_build/Tools/MeshUpgrader && /usr/bin/cmake -E cmake_link_script CMakeFiles/OgreMeshUpgrader.dir/link.txt - -verbose=1 /usr/bin/x86_64-pc-linux-gnu-g++ -march=native -pipe -ggdb -O2 -ftree-vectorize -msse -Wall -Winit-self -Wno-overloaded-virtual -Wcast-qual -Wwrite-strings -Wextra -Wno-unused-parameter -Wshadow -Wno-missing-field-initializers -Wno-long-long -Wno-unused-but-set-parameter -Wl,-O1 -Wl,--as-needed CMakeFiles/OgreMeshUpgrader.dir/src/main.cpp.o -o ../../bin/OgreMeshUpgrader -L/usr/lib64/x86_64-linux-gnu -rdynamic ../../lib/libOgreMain.so.1.9.0 /usr/lib64/x86_64-linux-gnu/libSM.so /usr/lib64/x86_64-linux-gnu/libICE.so /usr/lib64/x86_64-linux-gnu/libX11.so /usr/lib64/x86_64-linux-gnu/libXext.so /usr/lib64/x86_64-linux-gnu/libXt.so /usr/lib64/x86_64-linux-gnu/libXaw.so -lpthread -ldl /usr/lib64/x86_64-linux-gnu/libtbb.so /usr/lib64/x86_64-linux-gnu/libfreeimage.so /usr/lib64/x86_64-linux-gnu/libzzip.so -lz -latomic -Wl,-rpath,/home/portage/dev-games/ogre-1.9.0-r1/work/ogre-1.9.0_build/lib:/usr/lib64/x86_64-linux-gnu: ../../lib/libOgreMain.so.1.9.0: undefined reference to `void Ogre::ProgressiveMeshGenerator::addIndexDataImpl<unsigned short>(unsigned short*, unsigned short const*, std::vector<Ogre::ProgressiveMeshGenerator::PMVertex*, Ogre::STLAllocator<Ogre::ProgressiveMeshGenerator::PMVertex*, Ogre::CategorisedAllocPolicy<(Ogre::MemoryCategory)0> > >&, unsigned short)' collect2: error: ld returned 1 exit status Tools/MeshUpgrader/CMakeFiles/OgreMeshUpgrader.dir/build.make:96: recipe for target 'bin/OgreMeshUpgrader' failed make[2]: *** [bin/OgreMeshUpgrader] Error 1 ---- The reason is, that the ProgressiveMeshGenerator::addIndexDataImpl() template is only declared in the header, but defined in the compilation unit. Normally this would be fine, but the instantiations (one for short int, one for int) are used in the compilation unit for the QueuedProgressiveMeshGenerator, which is no longer legal. Each instantiation must be done in place, so the definition must be moved to the header. I have created a patch to build ogre-1.9.0 successfully on gentoo. It simply covers the definition in OgreMain/src/OgreProgressiveMeshGenerator.cpp with #if 0/#endif and adds the definition to OgreMain/include/OgreProgressiveMeshGenerator.h so it becomes visible to OgreMain/src/OgreQueuedProgressiveMeshGenerator.cpp. The attached patch fixes this. I have applied the patch to my ebuild dev-games/ogre-1.9.0-r3 - available from my overlay 'seden' via layman.
I have reported this upstream: https://ogre3d.atlassian.net/browse/OGRE-501
in portage. thanks for the bug report and patch.
