When using DWM, st or any utility that made using Clang which requires to manually patched up for adding new features you will need to use patch command.

To Patch Suckless utilities

patch -p1 < name of the patch.patch If you are your patch will be merged in the code without error but you get any hunk error check .rej file copy/add + commented lines and remove - commented lines into the respected filename files example if it generated dwc.c.rej file you make changes in dwc.c file

and rebuild and compile program with make build or make install