More robust error message on method compilation failure

Author: wsmoses

src/jlgen.jl

@@ -614,7 +614,9 @@ function ci_cache_populate(interp, cache, mi, min_world, max_world)
 
         # inference should have populated our cache
         wvc = WorldView(cache, min_world, max_world)
-        @assert CC.haskey(wvc, mi)
+        if !CC.haskey(wvc, mi)
+            throw(AssertionError("GPUCompiler: Failed to compile method for $mi, between worlds $min_world and $max_world"))
+        end
         ci = CC.getindex(wvc, mi)
 
         # if ci is rettype_const, the inference result won't have been cached
@@ -629,7 +631,10 @@ function ci_cache_populate(interp, cache, mi, min_world, max_world)
 
         # inference should have populated our cache
         wvc = WorldView(cache, min_world, max_world)
-        @assert CC.haskey(wvc, mi)
+
+        if !CC.haskey(wvc, mi)
+            throw(AssertionError("GPUCompiler: Failed to compile method for $mi, between worlds $min_world and $max_world"))
+        end
         ci = CC.getindex(wvc, mi)
 
         # if ci is rettype_const, the inference result won't have been cached