make runs into an error when trying to build after make clean

[DillonZChen]

make works the first time but not after the second time after running make clean

To reproduce:

make -j
make clean
make -j

Then I get the error after the second make command:

bison -v -d -o src/hddl.cpp src/hddl.y
flex --yylineno -o src/hddl-token.cpp src/hddl-token.l
g++ -O3 -pipe -Wall -Wextra -pedantic -std=c++17 -DNDEBUG -Wno-unused-parameter  -o src/hddl-token.o -c src/hddl-token.cpp
src/hddl-token.cpp:1559:17: warning: ‘void yyunput(int, char*)’ defined but not used [-Wunused-function]
 1559 |     static void yyunput (int c, char * yy_bp )
      |                 ^~~~~~~
g++ -O3 -pipe -Wall -Wextra -pedantic -std=c++17 -DNDEBUG -Wno-unused-parameter  -o src/hddl.o -c src/hddl.cpp
make: *** No rule to make target 'src/options.ggo', needed by 'src/cmdline.h'.  Stop.

I currently get around the issue by cloning the repository from scratch.

[galvusdamor]

Thanks for pointing this out! There is indeed an error in the makefile - namely that in make clean we remove *o and not *.o. I've just changed this. I.e. making after clean should now work correctly.