after a sequence of repetitive actions i realized the entire nodejs build process (which is largely not the nodejs build process but the v8 build process) is not actually compiling c++ code but instead
(1) generating header files from a combinatorial arrangement of shared stubs
(2) ordering the generated files to maximize the time the c++ compiler takes to iterate over non-matching entries for each #include
(3) directing the c++ compiler to include the maze of generated headers at the top of each source file
so the entire build process is stuck in VFS iteration, intentionally