There is a directory external/tinyxml (which actually refers to tinyxml2) in the source, it is referenced in hard in the Makefile. This is an example of compiling (ebuild tinyxml2-1.63-r1.ebuild compile) it using portage: x86_64-pc-linux-gnu-g++ -Ilib -Iexternals -Iexternals/tinyxml -DCFGDIR=\"/usr/share/cppcheck/cfg\" -O2 -pipe -mtune=native -c -o cli/threadexecutor.o cli/threadexecutor.cpp x86_64-pc-linux-gnu-g++ -O2 -pipe -mtune=native -c -o externals/tinyxml/tinyxml2.o externals/tinyxml/tinyxml2.cpp Reproducible: Always
Fixed in 1.64. Thanks for the report!