ferdium-app: FYI: what to do in case of "Skia shader compilation error" reports on the terminal (Linux)

Your issue

I updated my libdrm yesterday and rebuilt Mesa after that.

After retarting Ferdium this morning I got rendering issues and endless error messages on the calling terminal:

xdg-settings: unexpected/missing argument                                                                            
Try 'xdg-settings --help' for more information.                                                                      
MESA-INTEL: warning: ../mesa-21.0.1/src/intel/vulkan/anv_device.c:171: The kernel reported a GTT size larger than 2 GiB but not support for 48-bit addresses                                                                              
[29474:0711/142415.755573:ERROR:shared_context_state.cc(81)] Skia shader compilation error                           
------------------------                                                                                             
// Vertex SKSL                                                                                                       
#extension GL_NV_shader_noperspective_interpolation: require                                                         
uniform float4 sk_RTAdjust;uniform float3x3 umatrix_S1;in float2 position;in half4 color;in float2 localCoord;flat out half4 vcolor_S0;noperspective out float2 vTransformedCoords_2_S0;void main() {// Primitive Processor QuadPerEdgeAAGeometryProcessor                                                                                                     
vcolor_S0 = color;sk_Position = position.xy01;{                                                                      
vTransformedCoords_2_S0 = float3x2(umatrix_S1) * localCoord.xy1;                                                     
}                                                                                                                    
}                                                                                                                    
// Fragment SKSL                                                                                                     
#extension GL_NV_shader_noperspective_interpolation: require                                                         
uniform float3x3 umatrix_S1;uniform sampler2D uTextureSampler_0_S1;                                                  
flat in half4 vcolor_S0;noperspective in float2 vTransformedCoords_2_S0;half4 TextureEffect_S1_c0(half4 _input) {    
return sample(uTextureSampler_0_S1, vTransformedCoords_2_S0).rrrr;}                                                  

half4 MatrixEffect_S1(half4 _input) {
return TextureEffect_S1_c0(_input);
}

void main() {// Stage 0, QuadPerEdgeAAGeometryProcessor
half4 outputColor_S0;outputColor_S0 = vcolor_S0;const half4 outputCoverage_S0 = half4(1);half4 output_S1;output_S1 = MatrixEffect_S1(outputCoverage_S0);{ // Xfer Processor: Porter Duff
sk_FragColor = outputColor_S0 * output_S1;}}
// Vertex GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
uniform highp vec4 sk_RTAdjust;
uniform highp mat3 umatrix_S1;
in highp vec2 position;
in mediump vec4 color;
in highp vec2 localCoord;
flat out mediump vec4 vcolor_S0;
noperspective out highp vec2 vTransformedCoords_2_S0;
void main() {
    vcolor_S0 = color;
    gl_Position = vec4(position, 0.0, 1.0);
    {
        vTransformedCoords_2_S0 = mat3x2(umatrix_S1) * vec3(localCoord, 1.0);
    }
    gl_Position = vec4(gl_Position.xy * sk_RTAdjust.xz + gl_Position.ww * sk_RTAdjust.yw, 0.0, gl_Position.w);
}

// Fragment GLSL
#version 300 es
<SNIP>

Searching for “Skia shader compilation error” I found this ticket that also offered a solution:

https://bugs.chromium.org/p/chromium/issues/detail?id=1442633

The solution:

> find ~/.config/Ferdium/ -name "GPUCache" | xargs rm -rf

The strange thing is that Chromium does not report a change in the GL_RENDERER string.