--- cmake-3.19.1.ebuild.orig.txt	2020-11-29 18:40:57.000000000 -0600
+++ cmake-3.19.1.ebuild	2020-11-29 18:34:24.000000000 -0600
@@ -18,14 +18,15 @@
 SLOT="0"
 [[ "${PV}" = *_rc* ]] || \
 KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos ~sparc-solaris ~x64-solaris ~x86-solaris"
-IUSE="doc emacs ncurses qt5 test"
+IUSE="doc emacs ncurses qt5 +system-jsoncpp test"
+#system-jsoncpp is only meant to be disabled during prefix bootstrapping
 RESTRICT="!test? ( test )"
 
 RDEPEND="
 	>=app-arch/libarchive-3.3.3:=
 	app-crypt/rhash
 	>=dev-libs/expat-2.0.1
-	>=dev-libs/jsoncpp-1.9.2-r2:0=
+	system-jsoncpp? ( >=dev-libs/jsoncpp-1.9.2-r2:0= )
 	>=dev-libs/libuv-1.10.0:=
 	>=net-misc/curl-7.21.5[ssl]
 	sys-libs/zlib
@@ -77,6 +78,13 @@
 		-e '/"${cmake_bootstrap_dir}\/cmake"/s/^/#DONOTRUN /' \
 		bootstrap || die "sed failed"
 
+	local sdk_frameworks="${EPREFIX}/MacOSX.sdk/System/Library/Frameworks"
+	if [[ -d "${sdk_frameworks}" ]]; then
+		# ensure frameworks are found for darwin prefix
+		append-cflags $(test-flags-CC "-F${sdk_frameworks}")
+		append-cxxflags $(test-flags-CXX "-F${sdk_frameworks}")
+	fi
+
 	# execinfo.h on Solaris isn't quite what it is on Darwin
 	if [[ ${CHOST} == *-solaris* ]] ; then
 		sed -i -e 's/execinfo\.h/blablabla.h/' \
@@ -137,6 +145,9 @@
 		# where things are via GCC configuration and ldwrapper
 		sed -i -e '/cmake_gnu_set_sysroot_flag/d' \
 			Modules/Platform/Apple-GNU-C{,XX}.cmake || die
+		# disable isysroot usage with clang as well
+		sed -i -e '/_SYSROOT_FLAG/d' \
+			Modules/Platform/Apple-Clang.cmake || die
 	fi
 
 	# Add gcc libs to the default link paths
@@ -157,6 +168,7 @@
 
 	local mycmakeargs=(
 		-DCMAKE_USE_SYSTEM_LIBRARIES=ON
+		-DCMAKE_USE_SYSTEM_LIBRARY_JSONCPP=$(usex system-jsoncpp)
 		-DCMAKE_DOC_DIR=/share/doc/${PF}
 		-DCMAKE_MAN_DIR=/share/man
 		-DCMAKE_DATA_DIR=/share/${PN}