Added IMATH_INCLUDES to the cmake module

## Bug Report

### Build Problem

OTIO_IMATH_TARGETS is added to the cmake module so that applications using opentimelineio can inherit the correct library paths and libraries to link against, however IMATH_INCLUDES is not added to the cmake module. It specifies the include path for IMath header files included by files such as `opentimelineio/serializableObject.h`.

As a result, applications don't compile out of the box without discovering the correct IMath include path for themselves and manually adding it to the compiler's command line. The correct include path is needed to ensure the same version of IMath that opentimelineio was compiled against is referenced by the application.

For OTIO_IMATH_TARGETS, the `src/opentimelineio/CMakeLists.txt` file already does this:

```
target_link_libraries(opentimelineio
PUBLIC opentime ${OTIO_IMATH_TARGETS})
```

The same could be done for IMATH_INCLUDES by adding it to the public interface (it's only added to the private interface at the moment and hence not exported to the cmake module):

```
target_include_directories(opentimelineio
PUBLIC
$)
```

I've tested this change locally and it resolves the build error in the attached log.

## Expected Behavior

The cmake module provides application developers with the include path to the version of IMath that was discovered and used to build opentimelineio.

## Logs

```
mkdir -p /home/mark/projects/build/_linux_debug/otio/x86_64-linux-gnu && \
mkdir -p /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu && \
cd /home/mark/projects/build/_linux_debug/otio/x86_64-linux-gnu && \
cmake /home/mark/projects/demos/deps/otio/ \
-DCMAKE_INSTALL_PREFIX="/home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu" \
-DCMAKE_POSITION_INDEPENDENT_CODE=ON \
-DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
-DOTIO_INSTALL_PYTHON_MODULES=OFF \
-DOTIO_INSTALL_COMMANDLINE_TOOLS=OFF \
-DOTIO_INSTALL_CONTRIB=OFF \
-DOTIO_AUTOMATIC_SUBMODULES=OFF \
-DBUILD_SHARED_LIBS=OFF -DCMAKE_TOOLCHAIN_FILE="/opt/cmake-toolchains/toolchain-x86_64-linux-gnu.cmake" -DCMAKE_BUILD_TYPE=debug -DCMAKE_C_FLAGS="-I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include" -DCMAKE_CXX_FLAGS="-I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include" -DCMAKE_EXE_LINKER_FLAGS="" -DCMAKE_SHARED_LINKER_FLAGS="" -DCMAKE_MODULE_LINKER_FLAGS="" -DOTIO_SHARED_LIBS=OFF -DOTIO_SHARED_LIBS=OFF -DOTIO_SHARED_LIBS=OFF
-- OTIO C++ installing to /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu
-- Building static libs
-- Installing C++ bindings to: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu
-- Installing C++ dynamic libraries to: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib
-- Installing 'any' and 'nonstd' for C++ (OTIO_DEPENDENCIES_INSTALL=ON)
-- Install Python bindings: OFF
-- Building C++ with Coverage: OFF
-- Using src/deps/Imath by default
-- Imath is configuring as a cmake sub project
-- Configure Imath 3.2.0-dev, library API version: 29.0.0
-- Looking for sin in m
-- Looking for sin in m - found
-- Configuring done (0.1s)
-- Generating done (0.0s)
-- Build files have been written to: /home/mark/projects/build/_linux_debug/otio/x86_64-linux-gnu
cd /home/mark/projects/build/_linux_debug/otio/x86_64-linux-gnu && \
make -j8 --output-sync && \
make install
[ 10%] Building CXX object src/deps/Imath/src/Imath/CMakeFiles/Imath.dir/ImathRandom.cpp.o
[ 4%] Building CXX object src/deps/Imath/src/Imath/CMakeFiles/Imath.dir/ImathFun.cpp.o
[ 1%] Building CXX object src/opentime/CMakeFiles/opentime.dir/errorStatus.cpp.o
[ 3%] Building CXX object src/opentime/CMakeFiles/opentime.dir/rationalTime.cpp.o
[ 12%] Linking CXX static library libopentime.a
[ 12%] Built target opentime
[ 7%] Building CXX object src/deps/Imath/src/Imath/CMakeFiles/Imath.dir/ImathColorAlgo.cpp.o
[ 9%] Building CXX object src/deps/Imath/src/Imath/CMakeFiles/Imath.dir/ImathMatrixAlgo.cpp.o
[ 6%] Building CXX object src/deps/Imath/src/Imath/CMakeFiles/Imath.dir/half.cpp.o
[ 17%] Linking CXX static library libImath-3_2_d.a
[ 17%] Built target Imath
[ 15%] Building CXX object tests/CMakeFiles/test_opentime.dir/test_opentime.cpp.o
[ 14%] Building CXX object tests/CMakeFiles/test_opentime.dir/utils.cpp.o
[ 29%] Linking CXX executable test_opentime
[ 29%] Built target test_opentime
[ 28%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/errorStatus.cpp.o
[ 25%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/effect.cpp.o
[ 20%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/composable.cpp.o
[ 31%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/externalReference.cpp.o
[ 18%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/clip.cpp.o
[ 32%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/freezeFrame.cpp.o
[ 26%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/algo/editAlgorithm.cpp.o
[ 21%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/composition.cpp.o
[ 34%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/gap.cpp.o
[ 35%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/generatorReference.cpp.o
[ 23%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/deserialization.cpp.o
[ 37%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/imageSequenceReference.cpp.o
[ 40%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/linearTimeWarp.cpp.o
[ 42%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/marker.cpp.o
[ 39%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/item.cpp.o
[ 43%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/mediaReference.cpp.o
[ 45%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/missingReference.cpp.o
[ 46%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/safely_typed_any.cpp.o
[ 51%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/serializableObjectWithMetadata.cpp.o
[ 50%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/serializableObject.cpp.o
[ 48%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/serializableCollection.cpp.o
[ 57%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/stringUtils.cpp.o
[ 54%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/stack.cpp.o
[ 56%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/stackAlgorithm.cpp.o
[ 59%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/timeEffect.cpp.o
[ 60%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/timeline.cpp.o
[ 64%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/trackAlgorithm.cpp.o
[ 62%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/track.cpp.o
[ 70%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/CORE_VERSION_MAP.cpp.o
[ 65%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/transition.cpp.o
[ 68%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/unknownSchema.cpp.o
[ 53%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/serialization.cpp.o
[ 67%] Building CXX object src/opentimelineio/CMakeFiles/opentimelineio.dir/typeRegistry.cpp.o
[ 71%] Linking CXX static library libopentimelineio.a
[ 71%] Built target opentimelineio
[ 73%] Building CXX object tests/CMakeFiles/test_clip.dir/utils.cpp.o
[ 76%] Building CXX object tests/CMakeFiles/test_serializableCollection.dir/utils.cpp.o
[ 79%] Building CXX object tests/CMakeFiles/test_timeline.dir/utils.cpp.o
[ 81%] Building CXX object tests/CMakeFiles/test_serialization.dir/utils.cpp.o
[ 82%] Building CXX object tests/CMakeFiles/test_editAlgorithm.dir/utils.cpp.o
[ 79%] Building CXX object tests/CMakeFiles/test_track.dir/utils.cpp.o
[ 84%] Building CXX object tests/CMakeFiles/test_serialization.dir/test_serialization.cpp.o
[ 75%] Building CXX object tests/CMakeFiles/test_clip.dir/test_clip.cpp.o
[ 92%] Linking CXX executable test_serialization
[ 93%] Built target test_serialization
[ 93%] Linking CXX executable test_clip
[ 93%] Built target test_clip
[ 89%] Building CXX object tests/CMakeFiles/test_timeline.dir/test_timeline.cpp.o
[ 90%] Building CXX object tests/CMakeFiles/test_track.dir/test_track.cpp.o
[ 87%] Building CXX object tests/CMakeFiles/test_serializableCollection.dir/test_serializableCollection.cpp.o
[ 95%] Linking CXX executable test_timeline
[ 98%] Built target test_timeline
[ 96%] Linking CXX executable test_track
[ 98%] Built target test_track
[ 98%] Linking CXX executable test_serializableCollection
[ 98%] Built target test_serializableCollection
[ 85%] Building CXX object tests/CMakeFiles/test_editAlgorithm.dir/test_editAlgorithm.cpp.o
[100%] Linking CXX executable test_editAlgorithm
[100%] Built target test_editAlgorithm
[ 9%] Built target Imath
[ 14%] Built target opentime
[ 67%] Built target opentimelineio
[ 71%] Built target test_opentime
[ 76%] Built target test_clip
[ 81%] Built target test_serialization
[ 85%] Built target test_serializableCollection
[ 90%] Built target test_timeline
[ 95%] Built target test_track
[100%] Built target test_editAlgorithm
Install the project...
-- Install configuration: "debug"
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/deps/any/any.hpp
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/deps/nonstd/optional.hpp
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathConfig.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/pkgconfig/Imath.pc
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/cmake/Imath/ImathConfig.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/cmake/Imath/ImathConfigVersion.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/cmake/Imath/ImathTargets.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/cmake/Imath/ImathTargets-debug.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/libImath-3_2_d.a
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/half.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/halfFunction.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/halfLimits.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathBox.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathBoxAlgo.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathColor.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathColorAlgo.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathEuler.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathExport.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathForward.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathFrame.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathFrustum.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathFrustumTest.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathFun.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathGL.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathGLU.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathInt64.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathInterval.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathLine.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathLineAlgo.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathMath.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathMatrix.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathMatrixAlgo.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathNamespace.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathPlane.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathPlatform.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathQuat.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathRandom.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathRoots.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathShear.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathSphere.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathTypeTraits.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathVec.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/Imath/ImathVecAlgo.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentime/errorStatus.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentime/rationalTime.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentime/stringPrintf.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentime/timeRange.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentime/timeTransform.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentime/version.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/libopentime.a
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentime/OpenTimeTargets.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentime/OpenTimeTargets-debug.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentime/OpenTimeConfig.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/any.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/anyDictionary.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/anyVector.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/clip.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/composable.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/composition.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/deserialization.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/editAlgorithm.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/effect.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/errorStatus.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/externalReference.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/freezeFrame.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/gap.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/generatorReference.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/imageSequenceReference.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/item.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/linearTimeWarp.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/marker.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/mediaReference.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/missingReference.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/optional.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/safely_typed_any.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serializableCollection.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serializableObject.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serializableObjectWithMetadata.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serialization.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/stack.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/stackAlgorithm.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/timeEffect.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/timeline.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/track.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/trackAlgorithm.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/transition.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/typeRegistry.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/unknownSchema.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/vectorIndexing.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/version.h
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/lib/libopentimelineio.a
-- Old export file "/home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentimelineio/OpenTimelineIOTargets.cmake" will be replaced. Removing files [/home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentimelineio/OpenTimelineIOTargets-debug.cmake].
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentimelineio/OpenTimelineIOTargets.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentimelineio/OpenTimelineIOTargets-debug.cmake
-- Installing: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/share/opentimelineio/OpenTimelineIOConfig.cmake
mkdir -p /home/mark/projects/build/_linux_debug/otiotest/x86_64-linux-gnu && \
mkdir -p /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu && \
cd /home/mark/projects/build/_linux_debug/otiotest/x86_64-linux-gnu && \
cmake /home/mark/projects/demos/otiotest \
-DCMAKE_FIND_ROOT_PATH="/home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu" \
-DCMAKE_INSTALL_PREFIX="/home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu" \
-DCMAKE_BUILD_TYPE=debug \
-DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
-DCMAKE_C_FLAGS="-I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include" \
-DCMAKE_CXX_FLAGS="-I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include" \
-DCMAKE_TOOLCHAIN_FILE=/opt/cmake-toolchains/toolchain-x86_64-linux-gnu.cmake \
-DCMAKE_POSITION_INDEPENDENT_CODE=ON \
-DBUILD_SHARED_LIBS=OFF -DCMAKE_TOOLCHAIN_FILE="/opt/cmake-toolchains/toolchain-x86_64-linux-gnu.cmake" -DCMAKE_BUILD_TYPE=debug -DCMAKE_C_FLAGS="-I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include" -DCMAKE_CXX_FLAGS="-I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include" -DCMAKE_EXE_LINKER_FLAGS="" -DCMAKE_SHARED_LINKER_FLAGS="" -DCMAKE_MODULE_LINKER_FLAGS="" -DOTIO_SHARED_LIBS=OFF -DOTIO_SHARED_LIBS=OFF -DOTIO_SHARED_LIBS=OFF
-- The CXX compiler identification is GNU 11.4.0
-- The C compiler identification is GNU 11.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/x86_64-linux-gnu-g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/x86_64-linux-gnu-gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- CMAKE_MODULE_PATH:
-- CMAKE_CXX_FLAGS: -I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include
-- CMAKE_PREFIX_PATH:
-- CMAKE_INSTALL_PREFIX: /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu
-- CMAKE_INSTALL_LIBDIR: lib
-- CMAKE_INSTALL_INCLUDEDIR: include
-- CMAKE_SOURCE_DIR: /home/mark/projects/demos/otiotest
-- PROJECT_SOURCE_DIR: /home/mark/projects/demos/otiotest
-- CMAKE_CURRENT_SOURCE_DIR: /home/mark/projects/demos/otiotest
-- CMAKE_CURRENT_BINARY_DIR: /home/mark/projects/build/_linux_debug/otiotest/x86_64-linux-gnu
-- Configuring done (0.4s)
-- Generating done (0.0s)
-- Build files have been written to: /home/mark/projects/build/_linux_debug/otiotest/x86_64-linux-gnu
cd /home/mark/projects/build/_linux_debug/otiotest/x86_64-linux-gnu && \
make -j8 --output-sync && \
make install
[ 33%] Building CXX object CMakeFiles/otiotest.dir/main.cpp.o
In file included from /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serializableObjectWithMetadata.h:6,
from /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/effect.h:6,
from /home/mark/projects/demos/otiotest/otioschema.hpp:13,
from /home/mark/projects/demos/otiotest/main.cpp:12:
/home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serializableObject.h:16:10: fatal error: ImathBox.h: No such file or directory
16 | #include "ImathBox.h"
| ^~~~~~~~~~~~
compilation terminated.
make[3]: *** [CMakeFiles/otiotest.dir/build.make:76: CMakeFiles/otiotest.dir/main.cpp.o] Error 1
make[3]: *** Waiting for unfinished jobs....
[ 66%] Building CXX object CMakeFiles/otiotest.dir/otioschema.cpp.o
In file included from /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serializableObjectWithMetadata.h:6,
from /home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/effect.h:6,
from /home/mark/projects/demos/otiotest/otioschema.hpp:13,
from /home/mark/projects/demos/otiotest/otioschema.cpp:1:
/home/mark/projects/build/_linux_debug/install/x86_64-linux-gnu/include/opentimelineio/serializableObject.h:16:10: fatal error: ImathBox.h: No such file or directory
16 | #include "ImathBox.h"
| ^~~~~~~~~~~~
compilation terminated.
make[3]: *** [CMakeFiles/otiotest.dir/build.make:90: CMakeFiles/otiotest.dir/otioschema.cpp.o] Error 1
make[2]: *** [CMakeFiles/Makefile2:83: CMakeFiles/otiotest.dir/all] Error 2
make[1]: *** [Makefile:136: all] Error 2
make: *** [/home/mark/projects/buildtargets/demos/otiotest.mk:36: otiotest_x86_64-linux-gnu] Error 2
make: *** [Makefile:122: demos] Error 2
```

Start in src/opentimelineio/CMakeLists.txt, where OTIO_IMATH_TARGETS is public and the IMath include path is currently private; inspect the installed CMake module and exported target. Verify with the reported CMake configure, build, and install flow that a consuming application can include opentimelineio/serializableObject.h without manually adding IMath's include path.

Written by the indexing model from the issue text.