macOS: upgrade earliest supported version to 10.13

Prevent use of API newer than deployment target
Patch orc to prevent use of pthread_jit functions on 10.x

build.sh

@@ -44,14 +44,16 @@ for flavour in darwin-x64 darwin-arm64v8; do
     # Use pkg-config provided by Homebrew
     export PKG_CONFIG="$(brew --prefix)/bin/pkg-config --static"
 
-    # 10.9 should be a good minimal release target
-    export MACOSX_DEPLOYMENT_TARGET="10.9"
+    # Earliest supported version of macOS
+    export MACOSX_DEPLOYMENT_TARGET="10.13"
 
     # Added -fno-stack-check to workaround a stack misalignment bug on macOS 10.15
     # See:
     # https://forums.developer.apple.com/thread/121887
     # https://trac.ffmpeg.org/ticket/8073#comment:12
     export FLAGS="-fno-stack-check"
+    # Prevent use of API newer than the deployment target
+    export FLAGS+=" -Werror=unguarded-availability-new"
 
     if [ $PLATFORM = "darwin-arm64v8" ]; then
       # ARM64 builds work via cross compilation from an x86_64 machine

build/lin.sh

@@ -315,6 +315,10 @@ make install-strip
 mkdir ${DEPS}/orc
 $CURL https://gstreamer.freedesktop.org/data/src/orc/orc-${VERSION_ORC}.tar.xz | tar xJC ${DEPS}/orc --strip-components=1
 cd ${DEPS}/orc
+# Prevent detection of pthread_jit for macOS 10 deployment target
+if [ "$PLATFORM" == "darwin-x64" ]; then
+  sed -i'.bak' "s/cc.has_function('pthread_jit_write_protect_np')/false/" meson.build
+fi
 meson setup _build --default-library=static --buildtype=release --strip --prefix=${TARGET} ${MESON} \
   -Dorc-test=disabled -Dbenchmarks=disabled -Dexamples=disabled -Dgtk_doc=disabled -Dtests=disabled -Dtools=disabled
 ninja -C _build

darwin-x64/Toolchain.cmake

@@ -1,8 +1,8 @@
 SET(CMAKE_C_COMPILER clang)
 SET(CMAKE_CXX_COMPILER clang++)
 
-# 10.9 should be a good minimal release target
-SET(CMAKE_OSX_DEPLOYMENT_TARGET 10.9)
+# Earliest supported version of macOS
+SET(CMAKE_OSX_DEPLOYMENT_TARGET 10.13)
 
 set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)