If the repo submodule appears to be empty or out of date, you may need to run
git submodule update --init --checkout path/to/repo.
You may need to add #include <unistd.h> to xzoom.c for it to properly generate (otherwise main_0 goes missing). This include is normally only added with the TIMER macro enabled, but seems to be required for standard functionality. (We could fork the repo if we want to make this change explicit for the purposes of automated testing.)
clang>= 5.0sed
$ clang -MJ compile_commands.o.json xzoom.c -L/usr/X11R6/lib -lX11
$ sed -e '1s/^/[\n/' -e '$s/,$/\n]/' *.o.json > compile_commands.json
$ c2rust transpile compile_commands.json
$ rustc xzoom.rs -L/usr/X11R6/lib -lX11