add a note about building in mojave

README.md

@@ -121,6 +121,11 @@ echo 'export PATH="/usr/local/opt/gettext/bin:$PATH"' >> "$HOME"/.bash_profile
 
 If you run into a gettext error while building glib, try `brew link --force gettext` to override the built-in Mac OS BSD gettext with GNU GetText.
 
+*Note:* in Mojave (10.14) you need to set a minimum deployment version higher than 10.04. Otherwise you'll get the error `ld: library not found for -lgcc_s.10.4`.
+```
+export MACOSX_DEPLOYMENT_TARGET=10.09
+```
+
 The KOReader Android build requires `ant`, `openjdk-8-jdk` and `p7zip-full`. A compatible version of the Android NDK and SDK will be downloaded automatically by `./kodev build android` if no NDK or SDK is provided in environment variables. For that purpose you can use `NDK=/ndk/location SDK=/sdk/location ./kodev build android`.
 
 Users of Debian Jessie first need to configure the `backports` repository: