Fortran: Ninja generator fails on symlinked source dirs

I am on:

$ uname -a
FreeBSD deblndw011x.ad001.siemens.net 12.2-STABLE FreeBSD 12.2-STABLE #3 r369441: Fri Apr  9 14:09:31 CEST 2021
$ cmake --version
cmake version 3.20.1
$ ninja --version
1.10.2

Consider the following layout:

osipovmi@deblndw011x:~/DI-Programme-Portable
$ ll | grep lib
drwxr-xr-x  10 osipovmi  cad  8192 2021-05-03 20:06 _libcafe/
lrwxr-xr-x   1 osipovmi  cad    17 2021-05-08 20:26 libcafe_json@ -> _libcafe/CaFEJson
lrwxr-xr-x   1 osipovmi  cad    16 2021-05-08 20:26 libcafe_ket@ -> _libcafe/CaFEKet
lrwxr-xr-x   1 osipovmi  cad    18 2021-05-08 20:26 libcafe_plot@ -> _libcafe/CaFEPlot
lrwxr-xr-x   1 osipovmi  cad    20 2021-05-08 20:26 libcafe_smartld@ -> _libcafe/CaFESmartLD
drwxr-x---   6 osipovmi  cad  8192 2021-05-11 17:12 libmath/
drwxr-x---   6 osipovmi  cad  8192 2021-05-11 17:12 libsblm/
drwxr-x---   6 osipovmi  cad  8192 2021-05-11 17:12 libsbm/
drwxr-xr-x   6 osipovmi  cad  8192 2021-05-11 17:12 libsgram/
drwxr-x---   7 osipovmi  cad  8192 2021-05-11 17:12 libsm/

now try to generate Ninja files for libcafe_json:

osipovmi@deblndw011x:~/DI-Programme-Portable
$ cd libcafe_json/build/freebsd/
osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ rm -rf *
osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ echo $system_name
freebsd
osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ echo $generator
Ninja
osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ CC="gcc10" FC="gfortran10" cmake ../.. -G "$generator" "-DDIPROJ_CMAKE_MODULE_PATH=$HOME/DI-Programme-Portable/cmake" "-DCMAKE_INSTALL_PREFIX=$HOME/ldacafe/$system_name" -DDIPROJ_SYSTEM_TYPE=CaFE -DINSTALL_WITH_SUDO=OFF;
-- The C compiler identification is GNU 10.3.0
-- The Fortran compiler identification is GNU 10.3.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/local/bin/gcc10 - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting Fortran compiler ABI info
-- Detecting Fortran compiler ABI info - failed
-- Check for working Fortran compiler: /usr/local/bin/gfortran10
-- Check for working Fortran compiler: /usr/local/bin/gfortran10 - broken
CMake Error at /usr/local/share/cmake/Modules/CMakeTestFortranCompiler.cmake:51 (message):
  The Fortran compiler

    "/usr/local/bin/gfortran10"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: /net/home/osipovmi/DI-Programme-Portable/libcafe_json/build/freebsd/CMakeFiles/CMakeTmp

    Run Build Command(s):/usr/local/bin/ninja cmTC_43608 && [1/4] Building Fortran preprocessed CMakeFiles/cmTC_43608.dir/testFortranCompiler.f-pp.f
    [2/4] Generating Fortran dyndep file CMakeFiles/cmTC_43608.dir/Fortran.dd
    ninja: build stopped: CMakeFiles/cmTC_43608.dir/Fortran.dd:2: no build statement exists for '/net/home/osipovmi/DI-Programme-Portable/_libcafe/CaFEJson/build/freebsd/CMakeFiles/CMakeTmp/CMakeFiles/cmTC_43608.dir/testFortranCompiler.f.o'
    .





  CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
  CMakeLists.txt:3 (project)


-- Configuring incomplete, errors occurred!
See also "/net/home/osipovmi/DI-Programme-Portable/libcafe_json/build/freebsd/CMakeFiles/CMakeOutput.log".
See also "/net/home/osipovmi/DI-Programme-Portable/libcafe_json/build/freebsd/CMakeFiles/CMakeError.log".

Lets do now the same for make (BSD make):

osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ generator="Unix Makefiles"
osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ CC="gcc10" FC="gfortran10" cmake ../.. -G "$generator" "-DDIPROJ_CMAKE_MODULE_PATH=$HOME/DI-Programme-Portable/cmake" "-DCMAKE_INSTALL_PREFIX=$HOME/ldacafe/$system_name" -DDIPROJ_SYSTEM_TYPE=CaFE -DINSTALL_WITH_SUDO=OFF;
-- The C compiler identification is GNU 10.3.0
-- The Fortran compiler identification is GNU 10.3.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/local/bin/gcc10 - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting Fortran compiler ABI info
-- Detecting Fortran compiler ABI info - done
-- Check for working Fortran compiler: /usr/local/bin/gfortran10 - skipped
-- Checking whether /usr/local/bin/gfortran10 supports Fortran 90
-- Checking whether /usr/local/bin/gfortran10 supports Fortran 90 - yes
-- Setting build type to 'Debug' as none was specified on the command line
-- Configuring done
-- Generating done
-- Build files have been written to: /net/home/osipovmi/DI-Programme-Portable/libcafe_json/build/freebsd

Now go back to Ninja, and not use the symlink:

osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ generator="Ninja"
osipovmi@deblndw011x:~/DI-Programme-Portable/libcafe_json/build/freebsd (portable=)
$ cd ../../..
osipovmi@deblndw011x:~/DI-Programme-Portable
$ cd _libcafe/CaFEJson/build/freebsd/
osipovmi@deblndw011x:~/DI-Programme-Portable/_libcafe/CaFEJson/build/freebsd (portable=)
$ rm -rf *
osipovmi@deblndw011x:~/DI-Programme-Portable/_libcafe/CaFEJson/build/freebsd (portable=)
$ CC="gcc10" FC="gfortran10" cmake ../.. -G "$generator" "-DDIPROJ_CMAKE_MODULE_PATH=$HOME/DI-Programme-Portable/cmake" "-DCMAKE_INSTALL_PREFIX=$HOME/ldacafe/$system_name" -DDIPROJ_SYSTEM_TYPE=CaFE -DINSTALL_WITH_SUDO=OFF;
-- The C compiler identification is GNU 10.3.0
-- The Fortran compiler identification is GNU 10.3.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/local/bin/gcc10 - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting Fortran compiler ABI info
-- Detecting Fortran compiler ABI info - done
-- Check for working Fortran compiler: /usr/local/bin/gfortran10 - skipped
-- Checking whether /usr/local/bin/gfortran10 supports Fortran 90
-- Checking whether /usr/local/bin/gfortran10 supports Fortran 90 - yes
-- Setting build type to 'Debug' as none was specified on the command line
-- Configuring done
-- Generating done
-- Build files have been written to: /net/home/osipovmi/DI-Programme-Portable/_libcafe/CaFEJson/build/freebsd
osipovmi@deblndw011x:~/DI-Programme-Portable/_libcafe/CaFEJson/build/freebsd (portable=)
$ ls
build.ninja          cmake_install.cmake  CMakeCache.txt       CMakeFiles/          dilib.version

I don't know whether CMake fails here or Ninja, since Unix Makefiles generator works. If this isn't an issue with CMake I'd be happy to take this to Ninja devs.