Upgraded to Catalina 10.15 and had some breaking changes that I’d like to share:
1) /Developer directory has moved and can not be restored. Apple decided that the root directory / can only contain system directories and is not writeable by the user, period. The installer will move the affected files to /Users/Shared/XXX. I personally relied on this path in many places as it was a standard location for Mac developers.
2) /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk not longer exists so you need to change the SDK location to Xcode.app (see below), otherwise you’ll get the crt1.10.5.o linker error. The fpc.cfg file probably should be changed on your system and in future FPC releases.
3) Not FPC related but all 32-bit programs have been disabled so be careful about that.
4) Apps need to be notarized now. Here is my bash script which you can use https://github.com/neurolabusc/NotarizeFPC. This is for command line tools but can be modified for .app bundles by removing the info.plist part and zipping instead of making a disk image.
Installing Xcode 11.1 and command line tools didn’t have any side effects at least.