fix error in twoxtwo preprocess #321

Job	Run time
Run tests (ubuntu-22.04, false, ADD_CXXFLAGS=-fvisibility=hidden, sudo apt install -y -qq gfortra...	1m 27s
Run tests (ubuntu-24.04, false, ADD_CXXFLAGS=-fvisibility=hidden, sudo apt install -y -qq gfortra...	1m 27s
Run tests (macos-13, false, CC=gcc-13 CXX=g++-13 OSX=13 ADD_CXXFLAGS=-Wl,-ld_classic, brew instal...	2m 47s
Run tests (macos-14, false, CC=gcc-13 CXX=g++-13 OSX=14 ADD_CXXFLAGS=-Wl,-ld_classic, brew instal...	1m 53s
Run tests (ubuntu-22.04, true, ADD_CXXFLAGS=-fvisibility=hidden, sudo apt install -y -qq gfortran...	1m 32s
Run tests (macos-13, false, CC=clang OSX=13, brew install metis bash)	3m 2s
Run tests (ubuntu-24.04, true, ADD_CXXFLAGS=-fvisibility=hidden, sudo apt install -y -qq gfortran...	1m 27s
	13m 35s

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