I confirmed that Patch 2 is the culprit. Installing it immediately breaks compilation of packages in DEBUG config, if the package uses some methods from System.ZLib. The simple package attached, without any TMS Sparkle or TMS BCL dependency, does not compile.
ZLibTest.zip (4.9 KB)
I have open an issue in Quality Portal. You can try to vote it in the hope they give it higher priority: https://quality.embarcadero.com/browse/RSP-36641.