C3300 (F) Cannot open internal file
The ch38 C compiler simply quit working for me one day, leaving me only that error. It doesn't tell me which file it can't open, just that it fails. After a week and a half of back-and-forth with Renesas tech support, I finally figured it out on my own. The makefile I'm using has no "clean:" recipe, and I wanted to make absolutely sure I was rebuilding from scratch. So I deleted the obj/Debug directory where it puts its built object files. I assumed the compiler was smart enough to recreate any directory it needed. Boy, was I wrong. '
mkdir Debug' saved the day.
(I'm logging this simply so it hits the search engines, so others can benefit.)