### Compilation failed:

error: 1: variables of type 'testBlock' may not be uniform
layout(binding=456) uniform testBlock {
                            ^^^^^^^^^
error: 1: layout qualifier 'binding' is not permitted here
layout(binding=456) uniform testBlock {
^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: 1: interface blocks are not allowed in this kind of program
layout(binding=456) uniform testBlock {
                            ^^^^^^^^^
error: 5: 'main' must return: 'vec4', 'float4', or 'half4'
void main() {
^^^^^^^^^^^
error: 6: unknown identifier 'sk_FragColor'
    sk_FragColor = half4(half(test.x));
    ^^^^^^^^^^^^
error: 6: unknown identifier 'test'
    sk_FragColor = half4(half(test.x));
                              ^^^^
6 errors