I've forgotten to give the command line to compile (change "C:\lazarus\fpc\3.0.4\bin\x86_64-win64" to your fpc installation): C:\lazarus\fpc\3.0.4\bin\x86_64-win64\fpc.exe -MObjFPC -Scghi -O1 -g -gl -l -vewnhibq -Filib\x86_64-win64 -Fu..\pas-libusb\src -Fu. -FUlib\x86_64-win64 -FE. -olsusb.exe lsusb.lpr