add code to diagnose ci fails

Author: jw3126

test/cuda/layers.jl

@@ -22,6 +22,15 @@ const ACTIVATIONS = [identity, relu, tanh,
                      sigmoid, exp, softplus,
                      elu, selu]
 
+function test_approx(x,y; kw...)
+  pass = isapprox(x,y; kw...)
+  if !pass
+    kw = (;kw...)
+      @show norm(x) norm(y) norm(x-y) kw
+  end
+  @test pass
+end
+
 function gpu_gradtest(name::String, layers::Vector, x_cpu = nothing, args...; test_cpu = true)
   isnothing(x_cpu) && error("Missing input to test the layers against.")
   @testset "$name GPU grad tests" begin
@@ -50,10 +59,12 @@ function gpu_gradtest(name::String, layers::Vector, x_cpu = nothing, args...; te
 
           # test
           if test_cpu
+            test_approx(y_gpu, y_cpu, rtol=1f-3, atol=1f-3)
             @test y_gpu ≈ y_cpu rtol=1f-3 atol=1f-3
             if isnothing(xg_cpu)
               @test isnothing(xg_gpu)
             else
+              test_approx(Array(xg_gpu), xg_cpu, rtol=1f-3, atol=1f-3)
               @test Array(xg_gpu) ≈ xg_cpu rtol=1f-3 atol=1f-3
             end
           end
@@ -64,6 +75,7 @@ function gpu_gradtest(name::String, layers::Vector, x_cpu = nothing, args...; te
             else
               @test gs_gpu[p_gpu] isa Flux.CUDA.CuArray
               if test_cpu
+                test_approx(Array(gs_gpu[p_gpu]), gs_cpu[p_cpu], rtol=1f-3, atol=1f-3)
                 @test Array(gs_gpu[p_gpu]) ≈ gs_cpu[p_cpu] rtol=1f-3 atol=1f-3
               end
             end