20.4.0 fails to build with cmake: No such file exit_codes.mod

The debian package for packmol is set up to use cmake to configure and build packmol. It successfully managed v20.3.5, but updating to the latest v20.4.0 fails:

[ 50%] Building Fortran object CMakeFiles/packmol.dir/packmol.f90.o
/usr/bin/f95   -g -O2 -ffile-prefix-map=/build/packmol-20.4.0=. -fstack-protector-strong -Wall -c /build/packmol-20.4.0/packmol.f90 -o CMakeFiles/packmol.dir/packmol.f90.o
/build/packmol-20.4.0/gencan.f:2574:5:

 2574 |  1003 format(6X,I6,T22,D17.6,T43,D17.6)
      |     1
Warning: Label 1003 at (1) defined but not used [-Wunused-label]
/build/packmol-20.4.0/gencan.f:5662:5:

 5662 |   110 IF (DABS(DX(I)).LE.XMAX) GO TO 115
      |     1
Warning: Label 110 at (1) defined but not used [-Wunused-label]
/build/packmol-20.4.0/gencan.f:5661:5:

 5661 |    70 IF (DABS(DX(I)).GT.CUTLO) GO TO 75
      |     1
Warning: Label 70 at (1) defined but not used [-Wunused-label]
/build/packmol-20.4.0/gencan.f:5654:5:

 5654 |    50 IF (DX(I).EQ.ZERO) GO TO 200
      |     1
Warning: Label 50 at (1) defined but not used [-Wunused-label]
/build/packmol-20.4.0/gencan.f:5652:5:

 5652 |    30 IF (DABS(DX(I)).GT.CUTLO) GO TO 85
      |     1
Warning: Label 30 at (1) defined but not used [-Wunused-label]
/build/packmol-20.4.0/packmol.f90:36:7:

   36 |   use exit_codes
      |       1
Fatal Error: Cannot open module file 'exit_codes.mod' for reading at (1): No such file or directory
compilation terminated.
make[3]: *** [CMakeFiles/packmol.dir/build.make:286: CMakeFiles/packmol.dir/packmol.f90.o] Error 1
make[3]: *** Waiting for unfinished jobs....

It looks like handling of exit_codes.f90 is missing in CMakeLists.txt

m3g / packmol

20.4.0 fails to build with cmake: No such file exit_codes.mod #36