Using AVR Studio 4.18sp3, WinAVR.
The makefile generated by the IDE concludes with the line:
## Other dependencies -include $(shell mkdir dep 2>NUL) $(wildcard dep/*)
What does this line do? When I build the project from within AVR Studio, the project builds normally.
When I build the project (using the same Makefile, with slashes flipped) in Cygwin, it creates a NUL file in the ./default directory -- which I can only delete from within Cygwin (i.e., Windows can't delete it). When I delete the line, the project still builds successfully.
I think the ">NUL" part is telling it to dump some stuff in a file called NUL (hence the file creation), but I can't figure out what. I also don't know why it only creates the NUL file when I make it in Cygwin (and not when I make it within AVR Studio).