Please ensure that you have installed at least Xcode 12.2 and the Xcode 12.2 command line tools are active (see Xcode → Preferences → Locations → Command Line Tools).
To upgrade from a previous OS X / SDK version, please execute:
mv ${SECONDO_SDK} ${SECONDO_SDK}.old
Step 5 from the installation processs
If you have upgraded your Prolog Installation, please execute the following commands:
JPL=$(find /Applications -name "libjpl.dylib")
PL=$(find /Applications -name "libswipl.dylib")
SWIPLDIR=$(dirname $PL)
install_name_tool -add_rpath $SWIPLDIR $JPL
In your Secondo source directory please execute:
make clean
make
That is all, your Secondo SDK is successfully upgraded.