The problem is related to commit 506e2232a3. Between releases, the default behavior changed. Before, the option xrootd was disabled due to XRootD not being found, and now the builtin_xrootd option is turned ON instead, which requires openssl-dev. You can either install openssl-dev and keep support for XRootD enabled, or add -Dxrootd=OFF -Dbuiltin_xrootd=OFF to your build options to recover the previous behavior.