shaders in same file can't have different slot assignment?

[mattiasljungstrom]

If a shader file contains two shaders which use the same sampler name, but is assigned to different slots, the compilation will fail. I'm not sure if this is a bug or not, but I don't understand why it's required. It makes it hard to re-use code with blocks.

The same applies to uniform block names in different shaders in same file.

Example:

@vs vs
@glsl_options flip_vert_y
layout(location=0) in vec2 a_position;
out vec2 v_uv;

void main() {
    gl_Position = vec4(a_position, 0., 1.);
    v_uv = a_position * vec2(.5, -.5) + vec2(.5, .5);
}
@end

@fs fs_1
in vec2 v_uv;
out vec4 out_color;

layout(binding=0) uniform sampler2D s_texture;

void main() {
    vec3 color = texture(s_texture, v_uv).rgb;
    out_color = vec4(color, 1.0);
}
@end

@fs fs_2
in vec2 v_uv;
out vec4 out_color;

layout(binding=0) uniform sampler2D s_background;
layout(binding=1) uniform sampler2D s_texture;                      // error here

void main() {
    vec3 color = texture(s_background, v_uv).rgb + texture(s_texture, v_uv).rgb;
    out_color = vec4(color, 1.0);
}
@end

@program shader1 vs fs_1
@program shader2 vs fs_2

Error:

conflicting texture definitions found for 's_texture'

This example can be fixed trivially by switching s_background and s_texture slots, but it's not always that simple if you have more than two variants of the shader which uses different nr of textures. :)