CMake 4.2.1 Detecting C compiler ABI info - failed

Win11 Pro (x86-64)
cygwin 3.7.1
cmake 4.2.1
gcc 17.0.0

IN the first example of the cmake tutorial fails with the error above and as a result code to generate a target is not generated:

gmake[2]: *** No rule to make target ‘/d/home/skidmarks/Projects/Test/cmake/src/HelloWorld.cpp’, needed by ‘CMakeFiles/hello.dir/HelloWorld.cpp.o’. Stop.
gmake[1]: *** [CMakeFiles/Makefile2:87: CMakeFiles/hello.dir/all] Error 2
gmake: *** [Makefile:91: all] Error 2

It works on my desktop (same environment). The CMakeError log file is missing (from messages on stackoverlow and discourse.cmake.org), and I don’t know how to track down and fix my mistake. The cygwin path (> echo $PATH | tr ':' '\n') seems correct, and all compiles done with gcc/g++ outside of cmake work correctly. Both the C and C++ compilers are detected by cmake. But it fails for both the C/C++ checks on the ABI issue. Any idea how I can track down what in my environment is causing this failure?

The output of > cmake -Bbuild . is:

-- The C compiler identification is GNU 17.0.0
-- The CXX compiler identification is GNU 17.0.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc - works
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - failed
-- Check for working CXX compiler: /usr/bin/c++.exe
-- Check for working CXX compiler: /usr/bin/c++.exe - works
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done (5.3s)
-- Generating done (0.1s)
-- Build files have been written to: /d/home/skidmarks/Projects/Test/cmake/src/build

There are two areas which may be problematic. In cygwin, /usr/bin/cc is a symbolic link, /usr/bin/cc → gcc.exe and /usr/bin/c++ is an executable file (/usr/bin/c++.exe). I have to check this on my desktop but I believe it’s the same. So, the executables are found but the ABI can not be verified.