Duplicate symbols when building with QTC_STATIC_BUILD under flto

mkdir builddir
export CC=clang
export CXX=clang++
export AR=/usr/bin/llvm-ar
export RANLIB=/usr/bin/llvm-ranlib
export NM=/usr/bin/llvm-nm
export CFLAGS="-O3 -flto=thin -fno-plt -fno-semantic-interposition -ffat-lto-objects -fuse-ld=lld -Wl,--lto-O3 -Wl,-O3 -Wno-unused-command-line-argument"
export LDFLAGS="${CFLAGS}"
export CXXFLAGS="-fvisibility-inlines-hidden ${CFLAGS}"
cmake -G Ninja \
  -DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON \
  -DCMAKE_C_FLAGS_RELEASE="${CFLAGS}" \
  -DCMAKE_CXX_FLAGS_RELEASE="${CXXFLAGS}" \
  -DCMAKE_AR=/usr/bin/llvm-ar \
  -DCMAKE_NM=/usr/bin/llvm-nm \
  -DCMAKE_RANLIB=/usr/bin/llvm-ranlib \
  -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_INSTALL_LIBDIR=lib64 \
  -DCMAKE_INSTALL_PREFIX=/usr \
  -DWITH_TESTS=OFF \
  -DQTC_STATIC_BUILD=ON \
  -S . \
  -B builddir/

cmake --build builddir/

ld.lld: error: duplicate symbol: log() in modelindexer.cpp.o
ld.lld: error: duplicate symbol: log() in qtcreatorintegration.cpp.o