make falling over builtin rules ?

[Stefan Seefeld]

I have run into a situation where GNU make complains about circular 
dependencies, where there are none:

---

all: src.cu.o


src.cu.o: %.cu.o: %.cu
        @echo "compiling..."

---

will result in the message:

make: Circular src.cu <- src.cu.o dependency dropped.
compiling...

When I replace '.cu' by '.cc', the warning / error message goes away.
It also goes away if I disable builtin rules (via -r).

Can you please confirm whether this is a GNU make bug, or user error ?

Thanks,
                Stefan


--
Stefan Seefeld
CodeSourcery
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