Godot mac - freezes after assigning shader to shader material

[graphific]

Tested versions

• Reproducible in Godot 4.2.2-stable, 4.2.0, 4.0-stable, 4.0.rc1

System information

Mac air m1 - Godot v4.2.2.stable.official [15073af] - Vulkan (Forward+)

Issue description

I'm trying to import some synty assets (from the biome pack) into godot:

• Importing assets works fine (fbx and texture are there and can be loaded)

• To make the vegetation look good I'm using this shader which reproduces the unity specific tree shader: https://godotshaders.com/shader/synty-biomes-tree-compatible-shader/

• assigning the shader to a material and Godot hangs:

/Applications/Godot\ 4.2.2.app/Contents/MacOS/Godot -d sm_env_pine_03.tscn 
Godot Engine v4.2.2.stable.official.15073afe3 - https://godotengine.org
Vulkan API 1.2.231 - Forward+ - Using Vulkan Device #0: Apple - Apple M1
 
2024-05-16 22:54:53.215 Godot[35620:21004230] WARNING: AVCaptureDeviceTypeExternal is deprecated for Continuity Cameras. Please use AVCaptureDeviceTypeContinuityCamera and add NSCameraUseContinuityCameraDeviceType to your Info.plist.
(base) roelof@Roelofs-MacBook-Air TreeHut %  /Applications/Godot\ 4.2.2.app/Contents/MacOS/Godot -e sm_env_pine_03.tscn
Godot Engine v4.2.2.stable.official.15073afe3 - https://godotengine.org
Vulkan API 1.2.231 - Forward+ - Using Vulkan Device #0: Apple - Apple M1
 
2024-05-16 22:55:27.238 Godot[35691:21004970] WARNING: AVCaptureDeviceTypeExternal is deprecated for Continuity Cameras. Please use AVCaptureDeviceTypeContinuityCamera and add NSCameraUseContinuityCameraDeviceType to your Info.plist.
WARNING: Blend file import is enabled in the project settings, but no Blender path is configured in the editor settings. Blend files will not be imported.
     at: _editor_init (modules/gltf/register_types.cpp:63)
[mvk-error] VK_ERROR_DEVICE_LOST: MTLCommandBuffer "vkQueueSubmit CommandBuffer on Queue 0-0" execution failed (code 1): Discarded (victim of GPU error/recovery) (00000005:kIOGPUCommandBufferCallbackErrorInnocentVictim)
ERROR: Vulkan: Did not create swapchain successfully. Error code: VK_ERROR_DEVICE_LOST
   at: prepare_buffers (drivers/vulkan/vulkan_context.cpp:2459)
ERROR: Vulkan: Cannot submit graphics queue. Error code: VK_ERROR_DEVICE_LOST
   at: swap_buffers (drivers/vulkan/vulkan_context.cpp:2536)
ERROR: Vulkan: Did not create swapchain successfully. Error code: VK_ERROR_DEVICE_LOST
   at: prepare_buffers (drivers/vulkan/vulkan_context.cpp:2459)
ERROR: Vulkan: Cannot submit graphics queue. Error code: VK_ERROR_DEVICE_LOST
   at: swap_buffers (drivers/vulkan/vulkan_context.cpp:2536)

Steps to reproduce

The issue occurs when:

• create the gdshader using the godotshader one above = no errors all good so far.
• create a shader material, also good so far
• assign the shader to the material is when Godot hangs and shows:

Minimal reproduction project (MRP)

shader_mac_hang.zip

[graphific]

Some more findings:

• using a simplified shader its the last line ALPHA_SCISSOR_THRESHOLD = alpha_scissor_threshold; that causes the issue

shader_type spatial;

render_mode depth_prepass_alpha, cull_disabled, diffuse_burley, specular_schlick_ggx;

uniform float alpha_scissor_threshold = 0.4;
uniform float specular = 0.4;
uniform float roughness = 0.85;
uniform float face_tint = 0.2;

uniform sampler2D leaf_texture;
uniform sampler2D leaf_normal_texture;
uniform vec2 leaf_uv_scale = vec2(1.0);
uniform vec3 leaf_tint_base = vec3(0.0);
uniform vec3 leaf_tint_highlight = vec3(1.0);
uniform float leaf_tint_strength = 0.0;
uniform bool use_texture_brightness = true;
uniform float leaf_brightness = 8.0;

uniform vec3 leaf_emission_color = vec3(0.0);
uniform float leaf_emission_strength = 0.0;
uniform sampler2D leaf_emission_mask;

uniform sampler2D trunk_texture;
uniform sampler2D trunk_normal_texture;
uniform vec2 trunk_uv_scale = vec2(1.0);
uniform vec3 trunk_tint = vec3(0.0);
uniform float trunk_tint_strength = 0.0;

varying vec3 world_normal;
varying vec3 global_position;

float luminance(vec3 color) {
    return dot(color, vec3(0.299, 0.587, 0.114));
}

void vertex() {
	// Called for every vertex the material is visible on.
    global_position = MODEL_MATRIX[3].xyz;
    world_normal = normalize(MODEL_NORMAL_MATRIX * NORMAL);
}

void fragment() {
	// Called for every pixel the material is visible on.
	vec2 base_uv = COLOR.b > 0.5 ? UV * leaf_uv_scale : UV * trunk_uv_scale;
    vec4 base_texture = COLOR.b > 0.5 ? texture(leaf_texture, base_uv) : texture(trunk_texture, base_uv);
    vec4 base_normal = COLOR.b > 0.5 ? texture(leaf_normal_texture, base_uv) : texture(trunk_normal_texture, base_uv);

	vec3 tinted_color = mix(
        COLOR.b > 0.5 ? leaf_tint_base : trunk_tint,
        COLOR.b > 0.5 ? leaf_tint_highlight : trunk_tint,
        COLOR.g
    );
	
	float luminance_factor = (COLOR.b > 0.5 ? (use_texture_brightness ? luminance(base_texture.rgb) * leaf_brightness : 1.0) : 1.0);
    base_texture.rgb = mix(base_texture.rgb, tinted_color * luminance_factor, COLOR.b > 0.5 ? leaf_tint_strength : trunk_tint_strength);

    float face_tint_factor = sin(world_normal.y * 16.0);
    base_texture.rgb = COLOR.b < 0.5 ? mix(base_texture.rgb, base_texture.rgb * face_tint_factor, face_tint) : base_texture.rgb;

	SPECULAR = specular;
	NORMAL_MAP = base_normal.rgb;
	NORMAL = FRONT_FACING ? NORMAL : -NORMAL;
	ROUGHNESS = roughness;
	ALBEDO = base_texture.rgb;
	ALPHA = base_texture.a;
	EMISSION = COLOR.b > 0.5 ? leaf_emission_color * texture(leaf_emission_mask, base_uv).rgb * leaf_emission_strength : vec3(0.0);
	//ALPHA_SCISSOR_THRESHOLD = alpha_scissor_threshold;
}

Also here as a zip:
pine5.gdshader.zip