godot-cpp: Can't generate bindings

I downloaded a version of Godot from here: http://fixnum.org/godot/#latest_complete

And followed your instructions to generate the cpp bindings up to this point: scons p=linux target=bindings generate_bindings=yes

But get the following errors:

scons: Reading SConscript files … GLES3: max extensions: 356 GLES3: max ubo light: 409 GLES3: max ubo reflections: 455, ubo size: 144 ERROR: set_method_flags: Condition ’ !check->method_map.has(p_method) ’ is true. At: core/class_db.cpp:1008. ERROR: set_method_flags: Condition ’ !check->method_map.has(p_method) ’ is true. At: core/class_db.cpp:1008. ERROR: set_method_flags: Condition ’ !check->method_map.has(p_method) ’ is true. At: core/class_db.cpp:1008. ERROR: set_method_flags: Condition ’ !check->method_map.has(p_method) ’ is true. At: core/class_db.cpp:1008. mesege ERROR: _gl_debug_print: GL ERROR: Source: OpenGL Type: Performance ID: 131218 Severity: Medium Message: Program/shader state performance warning: Vertex shader in program 1 is being recompiled based on GL state. At: drivers/gles3/rasterizer_gles3.cpp:123. ERROR: load: No loader found for resource: res://godot_api.json At: core/io/resource_loader.cpp:213. ERROR: start: Failed loading scene: res://godot_api.json At: main/main.cpp:1462. WARNING: cleanup: ObjectDB Instances still exist! At: core/object.cpp:1910. ERROR: cleanup: There are still MemoryPool allocs in use at exit! At: core/dvector.cpp:69. IOError: [Errno 2] No such file or directory: ‘godot_api.json’: File “/home/pc/Applications/Godot/Godot3.0/SimpleLibrary/cpp_bindings/SConstruct”, line 71: binding_generator.generate_bindings(json_api_file) File “/home/pc/Applications/Godot/Godot3.0/SimpleLibrary/cpp_bindings/binding_generator.py”, line 9: classes = json.load(open(path))