Build issue with ctype_base.h

[thom-nic]

I'm trying to build Focal to work on some enhancements. This probably isn't an error with Focal per se but I'm not sure where else to ask and hoped you might have some idea of the cause. Here's what I'm seeing:

prebuilts/ndk/current/sources/cxx-stl/gnu-libstdc++/libs/armeabi-v7a/include/bits/ctype_base.h:46:35: error: '_U' was not declared in this scope
prebuilts/ndk/current/sources/cxx-stl/gnu-libstdc++/libs/armeabi-v7a/include/bits/ctype_base.h:47:32: error: '_L' was not declared in this scope
... lots more similar errors
make: *** [/home/thom/dev/android/out/target/product/grouper/obj/SHARED_LIBRARIES/libxmphelper_jni_intermediates/xmp_helper_jni.o] Error 1

building on Ubuntu Trusty x86_64, 3.13.0-24-generic kernel

I tried following suggestions here but it didn't seem to make a difference. Any ideas?

Thanks in advance!