makefile "no rule to make a target" error -

i have been looking @ problem while , still don't know wrong.

my makefile looks like:

    f90    = pgf90 netcdf_dir = /opt/netcdf  lbs             = -l$(netcdf_dir)/lib -lnetcdff -lnetcdf include_modules = -i$(netcdf_dir)/include  exec = cng_wrfchem_emi objs = module_cng_wrfchem_emi_lib.o \        cng_wrfchem_emi.o  ${exec} : ${objs}         ${f90} -o $@ ${objs} ${libs}  .f90.o:         ${f90} -c ${include_modules} $<  clean:         rm -f ${exec} ${objs} *.mod 

the error message is:

 make: *** no rule make target `module_cng_wrfchem_emi_lib.o', needed `cng_wrfchem_emi'.  stop. 

all files in same directory picture shows:

thanks

make doesn't know .f90 suffix, suffix rule not valid. it's not enough declare suffix rule if make doesn't know suffix. if want use suffix rules, have add new suffix .suffixes pseudo-target, this:

.suffixes: .f90 

or can use pattern rules, don't require (but gnu make-specific):

%.o : %.f90         ${f90} -c ${include_modules} $<