1### Compilation failed: 2 3error: 1: 'main' must return: 'vec4', 'float4', or 'half4' 4void main() { 5^^^^^^^^^^^ 6error: 5: discard statement is only permitted in fragment shaders 7 default: x = 1; discard; 8 ^^^^^^^ 9error: 7: unknown identifier 'sk_FragColor' 10 sk_FragColor = half4(x); 11 ^^^^^^^^^^^^ 123 errors 13