gcc "Too long" error

I keep getting this horrible error when I try to “make” something under some conditions which I haven’t pinpointed. I suspect something to do with path or filename lengths but I’m not sure.

Here’s an example from just now.
*make gcc -o librogpio -LOSlib -lOSLib32 librogpio.o Too long Makefile:12: recipe for target 'librogpio' failed make: *** [librogpio] Error 1

How do I make it go away?

Okay. I got it. I just renamed the files to libr. Shortening the filename did it. Now I can shift it back off the OS SD. I put it on there to get the path name as short as possible to see if that was the culprit.