Index: Setup/compile-interop-assembly-debug.sh
==================================================================
--- Setup/compile-interop-assembly-debug.sh
+++ Setup/compile-interop-assembly-debug.sh
@@ -3,11 +3,13 @@
 scriptdir=`dirname "$BASH_SOURCE"`
 extradefs="$@"
 
 if [[ "$OSTYPE" == "darwin"* ]]; then
   libname=libSQLite.Interop.dylib
-  gccflags="-arch i386 -arch x86_64"
+  # NOTE: No longer works in 10.14+
+  # gccflags="-arch i386 -arch x86_64"
+  gccflags="-arch x86_64"
 else
   libname=libSQLite.Interop.so
   gccflags=""
 fi
 

Index: Setup/compile-interop-assembly-release.sh
==================================================================
--- Setup/compile-interop-assembly-release.sh
+++ Setup/compile-interop-assembly-release.sh
@@ -3,11 +3,13 @@
 scriptdir=`dirname "$BASH_SOURCE"`
 extradefs="$@"
 
 if [[ "$OSTYPE" == "darwin"* ]]; then
   libname=libSQLite.Interop.dylib
-  gccflags="-arch i386 -arch x86_64"
+  # NOTE: No longer works in 10.14+
+  # gccflags="-arch i386 -arch x86_64"
+  gccflags="-arch x86_64"
 else
   libname=libSQLite.Interop.so
   gccflags=""
 fi