> Another thought: Can you delete the midas build directory and run cmake again? Like
> 
> $ cd midas/build
> $ rm -rf *
> $ cmake ..
> $ make VERBOSE=1
> 
> If you have the old build cache and upgraded your OS in meantime, the cache needs to be rebuild. The VERBOSE 
> flag tells you the compiler options, and you see where the compiler looks for the SDK directory.
> 
> Cheers,
> Stefan

Hi Stefan, 

Thanks again for your reply. Yes! the suggestion of rebuilding the cache was the right one, this is the output of cmake ..

Darrens-Mac-mini:~ betacage$ cd packages/midas/build/
Darrens-Mac-mini:build betacage$ rm -rf *
Darrens-Mac-mini:build betacage$ cmake ..
-- MIDAS: cmake version: 3.16.3
-- The C compiler identification is AppleClang 11.0.0.11000033
-- The CXX compiler identification is AppleClang 11.0.0.11000033
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- MIDAS: CMAKE_INSTALL_PREFIX: /Users/betacage/packages/midas
-- MIDAS: Found ROOT version 6.18/04
-- Found ZLIB: /usr/lib/libz.dylib (found version "1.2.11") 
-- MIDAS: Found ZLIB version 1.2.11
-- Found OpenSSL: /usr/lib/libcrypto.dylib (found version "1.1.1d")  
-- MIDAS: Found OpenSSL version 1.1.1d
-- MIDAS: MySQL not found
-- MIDAS: ODBC not found
-- MIDAS: SQLITE not found
-- MIDAS: nvidia-smi not found
-- Setting default build type to "RelWithDebInfo"
-- Found Git: /usr/bin/git (found version "2.21.1 (Apple Git-122.3)") 
-- MIDAS example/experiment: MIDAS in-tree-build
-- MIDAS: Found ZLIB version 1.2.11
-- MIDAS example/experiment: Found ROOT version 6.18/04
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/betacage/packages/midas/build


Unfortunately running make VERBOSE=1 the compilation crashes, with the following error 

[ 39%] Linking CXX executable mhttpd
cd /Users/betacage/packages/midas/build/progs && /Applications/CMake.app/Contents/bin/cmake -E cmake_link_script CMakeFiles/mhttpd.dir/link.txt 
--verbose=1
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++  -O2 -g -DNDEBUG -isysroot 
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -Wl,-search_paths_first -Wl,-
headerpad_max_install_names  CMakeFiles/mhttpd.dir/mhttpd.cxx.o CMakeFiles/mhttpd.dir/mongoose6.cxx.o CMakeFiles/mhttpd.dir/mgd.cxx.o 
CMakeFiles/mhttpd.dir/__/mscb/src/mscb.cxx.o  -o mhttpd  ../libmidas.a /usr/lib/libssl.dylib /usr/lib/libcrypto.dylib -lz 
ld: cannot link directly with dylib/framework, your binary is not an allowed client of /usr/lib/libcrypto.dylib for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [progs/mhttpd] Error 1
make[1]: *** [progs/CMakeFiles/mhttpd.dir/all] Error 2
make: *** [all] Error 2


Libcrypto seems to be part of the OpenSSL, so I am back to the original problem again. I did install OpenSSL via MacPorts. 

I have found this tread regarding this problem. But have to go and pick up my kids from school, so I don't have time to investigate today.
https://stackoverflow.com/questions/58446253/xcode-11-ld-error-your-binary-is-not-an-allowed-client-of-usr-lib-libcrypto-dy

Thanks again for staying with me and for responding so promptly. 

Berta