Error: Symbol 'test_co_sum' referenced at (1) not found in module 'collectives_test'

[Beliavsky]

I have GNU Fortran (GCC) 12.0.0 20210718 from equation.com installed on Windows 10. Running fpm build I get the error

 + gfortran -c test\main.f90  -Wall -Wextra -Wimplicit-interface -fPIC -fmax-errors=1 -g -fcheck=bounds -fcheck=array-temps -fbacktrace -fcoarray=single -J build\gfortran_2A42023B310FA28D\hope -I build\gfortran_2A42023B310FA28D\hope  -o build\gfortran_2A42023B310FA28D\hope\test_main.f90.o
test\main.f90:8:35:

    8 |         use collectives_test, only: &
      |                                   1
Error: Symbol 'test_co_sum' referenced at (1) not found in module 'collectives_test'
compilation terminated due to -fmax-errors=1.
<ERROR> Compilation failed for object " test_main.f90.o "
<ERROR>stopping due to failed compilation
STOP 1