auto_unbox error weirdness

auto_unbox-error.jl

julia> using Combinatorics

julia> function foo()
           ts = filter(x->isa(x, DataType), map(eval, names(Base)))
           for x in ts
           end
           permutations(ts, 2)
       end
foo (generic function with 1 method)

julia> foo()
Combinatorics.Permutations{Array{Any,1}}(Any[Pair{A,B},AbstractChannel,AbstractRNG,AbstractSparseArray{Tv,Ti,N},ArgumentError,Array{T,N},AssertionError,Associative{K,V},Base64DecodePipe,Base64EncodePipe  …  Union,UnitRange{T<:Real},UpperTriangular{T,S<:AbstractArray{T,2}},Val{T},VersionNumber,UTF32String,WeakKeyDict{K,V},WorkerConfig,WorkerPool,Zip{I,Z<:Base.AbstractZipIterator}],2)

julia> @code_lowered foo()
1-element Array{Any,1}:
 LambdaInfo for foo
:(begin  # REPL[2], line 2:
        #1 = $(Expr(:new, :(Main.##1#2)))
        GenSym(0) = #1
        GenSym(1) = (Main.map)(Main.eval,(Main.names)(Main.Base))
        ts = (Main.filter)(GenSym(0),GenSym(1)) # REPL[2], line 3:
        GenSym(2) = ts
        #temp# = (top(start))(GenSym(2))
        9: 
        unless (top(!))((top(done))(GenSym(2),#temp#)) goto 16
        GenSym(3) = (top(next))(GenSym(2),#temp#)
        x = (top(getfield))(GenSym(3),1)
        #temp# = (top(getfield))(GenSym(3),2)
        14: 
        goto 9
        16: 
        17:  # REPL[2], line 5:
        return (Main.permutations)(ts,2)
    end)

julia> @code_typed foo()
1-element Array{Any,1}:
 LambdaInfo for foo
:(begin  # REPL[2], line 2:
        #1 = $(Expr(:new, :(Main.##1#2)))
        GenSym(0) = #1 # reflection.jl, line 32: # reflection.jl, line 30:
        GenSym(4) = (Base.box)(Int32,(Base.zext_int)(Int32,false))
        GenSym(5) = (Base.box)(Int32,(Base.zext_int)(Int32,false))
        GenSym(1) = (Main.map)(Main.eval,(Base.sort!)((top(ccall))(:jl_module_names,(top(apply_type))(Base.Array,Base.Symbol,1)::Type{Array{Symbol,1}},(top(svec))(Base.Any,Base.Int32,Base.Int32)::SimpleVector,Main.Base,0,GenSym(4),0,GenSym(5),0)::Array{Symbol,1})::Array{Symbol,1})::AbstractArray{T,N}
        ts = (Main.filter)(GenSym(0),GenSym(1)) # REPL[2], line 3:
        GenSym(2) = ts
        #temp# = (top(start))(GenSym(2))
        13: 
        unless (top(!))((top(done))(GenSym(2),#temp#)) goto 20
        GenSym(3) = (top(next))(GenSym(2),#temp#)
        x = (top(getfield))(GenSym(3),1)
        #temp# = (top(getfield))(GenSym(3),2)
        18: 
        goto 13
        20: 
        21:  # REPL[2], line 5:
        return (Main.permutations)(ts,2)::Combinatorics.Permutations{T}
    end::Combinatorics.Permutations{T})

julia> function foo()
           ts = filter(x->isa(x, DataType), map(eval, names(Base)))
           for x in ts
           end
           permutations(ts, 2)
       end
WARNING: Method definition foo() in module Main at REPL[2]:2 overwritten at REPL[6]:2.
foo (generic function with 1 method)

julia> foo()
ERROR: auto_unbox: unable to determine argument type
 [inlined code] from /Users/isaac/.julia/v0.5/Combinatorics/src/permutations.jl:30
 in foo() at ./REPL[6]:5
 in eval(::Module, ::Any) at ./boot.jl:236

julia> @code_lowered foo()
1-element Array{Any,1}:
 LambdaInfo for foo
:(begin  # REPL[6], line 2:
        #3 = $(Expr(:new, :(Main.##3#4)))
        GenSym(0) = #3
        GenSym(1) = (Main.map)(Main.eval,(Main.names)(Main.Base))
        ts = (Main.filter)(GenSym(0),GenSym(1)) # REPL[6], line 3:
        GenSym(2) = ts
        #temp# = (top(start))(GenSym(2))
        9: 
        unless (top(!))((top(done))(GenSym(2),#temp#)) goto 16
        GenSym(3) = (top(next))(GenSym(2),#temp#)
        x = (top(getfield))(GenSym(3),1)
        #temp# = (top(getfield))(GenSym(3),2)
        14: 
        goto 9
        16: 
        17:  # REPL[6], line 5:
        return (Main.permutations)(ts,2)
    end)

julia> @code_typed foo()
1-element Array{Any,1}:
 LambdaInfo for foo
:(begin  # REPL[6], line 2:
        #3 = $(Expr(:new, :(Main.##3#4)))
        GenSym(0) = #3 # reflection.jl, line 32: # reflection.jl, line 30:
        GenSym(4) = (Base.box)(Int32,(Base.zext_int)(Int32,false))
        GenSym(5) = (Base.box)(Int32,(Base.zext_int)(Int32,false))
        GenSym(6) = (Base.sort!)((top(ccall))(:jl_module_names,(top(apply_type))(Base.Array,Base.Symbol,1)::Type{Array{Symbol,1}},(top(svec))(Base.Any,Base.Int32,Base.Int32)::SimpleVector,Main.Base,0,GenSym(4),0,GenSym(5),0)::Array{Symbol,1})::Array{Symbol,1} # abstractarray.jl, line 1119: # generator.jl, line 10: # generator.jl, line 10:
        (top(getfield))(Base,:Generator)::Type{Base.Generator{I,F}}
        GenSym(1) = (Base.collect_similar)(GenSym(6),$(Expr(:new, Base.Generator{Array{Symbol,1},Core.#eval}, :(Main.eval), GenSym(6))))::AbstractArray{T,N}
        ts = (Main.filter)(GenSym(0),GenSym(1)) # REPL[6], line 3:
        GenSym(2) = ts
        #temp#@_4 = (top(start))(GenSym(2))
        18: 
        unless (top(!))((top(done))(GenSym(2),#temp#@_4)) goto 25
        GenSym(3) = (top(next))(GenSym(2),#temp#@_4)
        x = (top(getfield))(GenSym(3),1)
        #temp#@_4 = (top(getfield))(GenSym(3),2)
        23: 
        goto 18
        25: 
        26:  # REPL[6], line 5:
        #temp#@_6 = 2 # /Users/isaac/.julia/v0.5/Combinatorics/src/permutations.jl, line 30:
        unless (Base.slt_int)(#temp#@_6,0)::Bool goto 33 # /Users/isaac/.julia/v0.5/Combinatorics/src/permutations.jl, line 31:
        #temp#@_6 = (Combinatorics.length)(ts) + 1
        33:  # /Users/isaac/.julia/v0.5/Combinatorics/src/permutations.jl, line 33:
        return (Combinatorics.Permutations)(ts,#temp#@_6)::Combinatorics.Permutations{T}
    end::Combinatorics.Permutations{T})