title: Referenced at (1) not found in module in macbook monterey
body: <p>I tried to compile the code <a href="https://github.com/msg-byu/enumlib" rel="nofollow noreferrer">https://github.com/msg-byu/enumlib</a> using gfortran on my macbook. However, it showed the following error.</p>
  <pre><code> use io_utils, only: co_ca
                     1
  Error: Symbol ‘co_ca’ referenced at (1) not found in module ‘io_utils’
  make: *** [makeStr.o] Error 1
  </code></pre>
  <p>I tried to add -cpp flag but it did not worked. Could you please help me out?
  Here is the Makefile.</p>
  <p>When I added <code>co_ca</code> to define in <code>public</code>, it worked but showed some warnings like the following:</p>
  <pre><code>gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c io_utils.f90
  io_utils.f90:52:98:
  
     52 |   subroutine read_struct_enum_out(title,LatDim,pLV,nD,d,k,eq,Nmin,Nmax,eps,full,label,digit,cRange,fname)
        |                                                                                                  1
  Warning: Unused dummy argument ‘crange’ at (1) [-Wunused-dummy-argument]
  gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c arrow_related.f90
  gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c tree_class.f90
  tree_class.f90:483:18:
  
    483 |           index = index + binomial(nLeft-site_i, count(new_labeling(site_i:)==1)-1)
        |                  1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  tree_class.f90:224:14:
  
    224 |           I = I - nchoosek(ell-1,t-1)
        |              1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  tree_class.f90:110:37:
  
    110 |           self%branches(species_i) = nchoosek(sum(self%colors(species_i:)),self%colors(species_i))
        |                                     1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c labeling_related.f90
  labeling_related.f90:1624:9:
  
   1624 |     nl = multinomial(iConc)
        |         1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  labeling_related.f90:1550:18:
  
   1550 |           count = count + (-1)**p*nchoosek(m,p)*tc
        |                  1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  labeling_related.f90:942:8:
  
    942 |     x = idx
        |        1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  labeling_related.f90:946:14:
  
    946 |        bnml = binomial(i-1,t-1)
        |              1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  labeling_related.f90:918:21:
  
    918 |              xTemp = xTemp + binomial(nLeft - iM, count(mask(iM:)==1)-1)
        |                     1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  labeling_related.f90:888:15:
  
    888 |        C(iK) = binomial(nLeft,conc(iK))
        |               1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  labeling_related.f90:727:20:
  
    727 |              quot = labIndx/multiplier(ilab) ! How many times does k(i) divide the number
        |                    1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  labeling_related.f90:310:83:
  
    310 |   SUBROUTINE generate_permutation_labelings(k,n,nD,perm,lab,iConc,parLabel,parDigit,degeneracy_list,fixed_cells)
        |                                                                                   1
  Warning: Unused dummy argument ‘pardigit’ at (1) [-Wunused-dummy-argument]
  labeling_related.f90:58:64:
  
     58 |   SUBROUTINE recursively_stabilized_enum(perm,conc,symsize,knary,SNF,LT,HNF,HNFcnt,hnf_degen,nfound,scount,fixOp,iBlock,equivalencies,inactives,permIndx,allowed,fixedcell,aperms)
        |                                                                1
  Warning: Unused dummy argument ‘knary’ at (1) [-Wunused-dummy-argument]
  labeling_related.f90:1487:35:
  
   1487 |   SUBROUTINE make_translation_group(d,trans)
        |                                   ^
  Warning: ‘make_translation_group’ defined but not used [-Wunused-function]
  labeling_related.f90:1583:52:
  
   1583 |   SUBROUTINE generate_disjoint_permutation_labelings(k,n,nD,perm,lab,iConc,parLabel,parDigit)
        |                                                    ^
  Warning: ‘generate_disjoint_permutation_labelings’ defined but not used [-Wunused-function]
  gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c enumeration_routines.f90
  gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c derivative_structure_generator.f90
  derivative_structure_generator.f90:1600:17:
  
   1600 |     size_count = size_count + this_count*nHNF
        |                 1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  derivative_structure_generator.f90:1601:18:
  
   1601 |     total_count = total_count + this_count*nHNF
        |                  1
  Warning: Possible change of value in conversion from INTEGER(8) to INTEGER(4) at (1) [-Wconversion]
  gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c enumeration_utilities.f90
  enumeration_utilities.f90:86:57:
  
     86 |     if (minkowskiReduce) call minkowski_reduce_basis(sLV,sLV,eps)
        |                                                         1
  Warning: Same actual argument associated with INTENT(OUT) argument ‘out’ and INTENT(IN) argument ‘in’ at (1)
  ar ru libenum.a sorting.o enumeration_types.o io_utils.o arrow_related.o tree_class.o labeling_related.o enumeration_routines.o derivative_structure_generator.o enumeration_utilities.o
  ar: creating archive libenum.a
  ranlib  libenum.a
  gfortran -fPIC -g -fbounds-check -Wall -ffree-line-length-none -fno-underscoring -I../symlib/src -c ../aux_src/makeStr.f90
  ../aux_src/makeStr.f90:13:67:
  
     13 | integer ioerr, iline, ic, i, ilab, pgOps, nD, hnfN, iAt, jAt, iSpec, nSpec, idx, foutput_unit
        |                                                                   1
  Warning: Unused variable ‘ispec’ declared at (1) [-Wunused-variable]
  gfortran  -o makestr.x makeStr.o libenum.a ../symlib/src/libcomparestructs.a ../symlib/src/libutils.a ../symlib/src/libsym.a ../symlib/src/librational.a ../symlib/src/libcombinatorics.a
  </code></pre>