Unit test binary fails to link with missing bullet symbols

[apteryks]

Hi,

I have built Ogre with bullet support, and MyGUI builds fine unless I enable the unit tests with: -DMYGUI_BUILD_UNITTESTS=TRUE. When I do, the build fails with link errors:

[ 70%] Linking CXX executable ../../bin/UnitTest_AttachDetach
cd /tmp/guix-build-mygui-3.4.3.drv-0/build/UnitTests/UnitTest_AttachDetach && /gnu/store/jjxafj2r8np0ay9q6y554xj7b32dxn98-cmake-minimal-3.24.2/bin/cmake -E cmake_link_script CMakeFiles/UnitTest_AttachDetach.dir/link.txt --verbose=1
/gnu/store/86fc8bi3mciljxz7c79jx8zr4wsx7xw8-gcc-11.4.0/bin/c++ -O2 -g -DNDEBUG CMakeFiles/UnitTest_AttachDetach.dir/DemoKeeper.cpp.o -o ../../bin/UnitTest_AttachDetach  -Wl,-rpath,/tmp/guix-build-mygui-3.4.3.drv-0/build/lib:/gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib ../../lib/libMyGUICommon.a /gnu/store/y9b30vxc27wymy861la2j0bj6i7wd8gf-sdl2-2.30.1/lib/libSDL2.so ../../lib/libMyGUI.OgrePlatform.a ../../lib/libMyGUIEngine.so.3.4.3 -ldl /gnu/store/7ah6i5829f5ha6bdfzcj1gf21115xyyd-freetype-2.13.0/lib/libfreetype.so /gnu/store/1prv14v6jfnzzg7szm57690b7fr6sx33-zlib-1.3/lib/libz.so /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreBites.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreBullet.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libBulletDynamics.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libBulletCollision.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libLinearMath.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libBulletSoftBody.so /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreMeshLodGenerator.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreOverlay.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreProperty.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreTerrain.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgrePaging.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreRTShaderSystem.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreVolume.so.14.3 /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreMain.so.14.3 -lpthread /gnu/store/y9b30vxc27wymy861la2j0bj6i7wd8gf-sdl2-2.30.1/lib/libSDL2.so 
ld: /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreBullet.so: undefined reference to `btConvexHullShape::btConvexHullShape(float const*, int, int)'
ld: /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreBullet.so: undefined reference to `btCapsuleShape::btCapsuleShape(float, float)'
ld: /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreBullet.so: undefined reference to `btRigidBody::btRigidBody(float, btMotionState*, btCollisionShape*, btVector3 const&)'
ld: /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreBullet.so: undefined reference to `btCapsuleShapeZ::btCapsuleShapeZ(float, float)'
ld: /gnu/store/ai8h4fwkx6cr7lxq77pwah6x8cpqzji2-ogre-14.3.1/lib/libOgreBullet.so: undefined reference to `btCapsuleShapeX::btCapsuleShapeX(float, float)'
collect2: error: ld returned 1 exit status
make[2]: *** [UnitTests/UnitTest_AttachDetach/CMakeFiles/UnitTest_AttachDetach.dir/build.make:121: bin/UnitTest_AttachDetach] Error 1
make[2]: Leaving directory '/tmp/guix-build-mygui-3.4.3.drv-0/build'
make[1]: *** [CMakeFiles/Makefile2:577: UnitTests/UnitTest_AttachDetach/CMakeFiles/UnitTest_AttachDetach.dir/all] Error 2
make[1]: Leaving directory '/tmp/guix-build-mygui-3.4.3.drv-0/build'
make: *** [Makefile:139: all] Error 2
error: in phase 'build': uncaught exception:
%exception #<&invoke-error program: "make" arguments: ("-j" "1") exit-status: 2 term-signal: #f stop-signal: #f> 
phase `build' failed after 72.3 seconds
command "make" "-j" "1" failed with status 2
build process 18 exited with status 256
builder for `/gnu/store/8vcam46drywwgp8jxzplyyjhnljc9drc-mygui-3.4.3.drv' failed with exit code 1

I'm guessing the issue may be a link order problem that is more likely to happen when dealing with static libraries, as explained here: https://stackoverflow.com/a/409402/2896799, but I haven't investigated yet.

[apteryks]

It's definitely an issue with order-sensitive linkers such as the GNU bfd linker. When I used mold instead, which is order-insensitive, I can link the binary (here with GCC 11.4):

/gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/bin/c++ -B/gnu/store/xz2bsimic6wddhdajmmphn6k90nz077c-mold-2.34.1/libexec/mold -O2 -g -DNDEBUG CMakeFiles/UnitTest_AttachDetach.dir/DemoKeeper.cpp.o -o ../../bin/UnitTest_AttachDetach   -L/usr/local/lib  -Wl,-rpath,/usr/local/lib:/home/maxim/src/mygui/build/lib64:/gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib ../../lib64/libMyGUIEngine.so.3.4.4 -ldl /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libfreetype.so /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libz.so /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreBites.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreBullet.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libBulletDynamics.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libBulletCollision.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libLinearMath.so /gnu/store/v6papmny5q52dn4w6rh6g3aiwiw91g6q-bullet-3.25/lib/libBulletSoftBody.so /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreMeshLodGenerator.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreOverlay.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreProperty.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreTerrain.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgrePaging.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreRTShaderSystem.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreVolume.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libOgreMain.so.14.3 /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libSDL2.so ../../lib64/libMyGUICommon.a ../../lib64/libMyGUI.OgrePlatform.a -lpthread /gnu/store/wziqn1lznvizrc41wpadb6inrwr315dn-profile/lib/libSDL2.so 

Note -B/gnu/store/xz2bsimic6wddhdajmmphn6k90nz077c-mold-2.34.1/libexec/mold, which causes the ld used to be that of mold for GCC 11.

[apteryks]

Might be an issue in Ogre built with bullet; I've turned all the static libraries in this project to shared ones and still had the problem with the traditional GNU linker.