I hope this isn't too far afield of your question, but it's worth noting that you can keep old SDKs around to use after upgrading Xcode. It's not a bad idea to backup the contents of the following folders before an upgrade:
$(xcode-select --print-path)/Platforms/*/Developer/SDKs
The old SDKs can be copied back in after the upgrade. Obviously, it's better to use the latest SDK whenever possible, but sometimes deadlines and development realities make it necessary to continue with a working SDK until code can be re-worked.
This process can also be performed semi-automatically. Simply install the latest Xcode version in a new location (keeping the old version untouched) and link the existing SDKs with the following script:
platforms_path="$1/Contents/Developer/Platforms";
if [ -d $platforms_path ]; then
for platform in `ls $platforms_path`
do
sudo ln -sf $platforms_path/$platform/Developer/SDKs/* $(xcode-select --print-path)/Platforms/$platform/Developer/SDKs;
done;
fi;
You just need to supply it with the path to the old .app
:
./xcode.sh /Applications/Xcode-463.app
More information in this question:
You can find old versions of Xcode here: