Internal error constructing NTuple

[yurivish]

Reduced case, on Julia 1.1.0:

(NTuple is supposed to be NTuple{N, T} and the example has this backwards, but an internal error is unexpected.)

julia> struct Foo
           xs::NTuple{<:Any, 3}
           Foo(xs...) = new(xs)
       end

julia> Foo(1, 2, 3)
Internal error: encountered unexpected error in runtime:
TypeError(func=:UnionAll, context="", expected=Type, got=3)
rec_backtrace at /Users/osx/buildbot/slave/package_osx64/build/src/stackwalk.c:94
record_backtrace at /Users/osx/buildbot/slave/package_osx64/build/src/task.c:217 [inlined]
jl_throw at /Users/osx/buildbot/slave/package_osx64/build/src/task.c:417
jl_type_error_rt at /Users/osx/buildbot/slave/package_osx64/build/src/rtutils.c:118
jl_type_error at /Users/osx/buildbot/slave/package_osx64/build/src/rtutils.c:125
jl_type_unionall at /Users/osx/buildbot/slave/package_osx64/build/src/jltypes.c:521
Type at ./boot.jl:353
rewrap_unionall at ./essentials.jl:209 [inlined]
fieldtype_tfunc at ./compiler/tfuncs.jl:877
jl_apply at /Users/osx/buildbot/slave/package_osx64/build/src/./julia.h:1571 [inlined]
jl_f__apply at /Users/osx/buildbot/slave/package_osx64/build/src/builtins.c:556
builtin_tfunction at ./compiler/tfuncs.jl:1286
builtin_tfunction at ./compiler/tfuncs.jl:1200 [inlined]
abstract_call at ./compiler/abstractinterpretation.jl:593
abstract_eval_call at ./compiler/abstractinterpretation.jl:805
abstract_eval at ./compiler/abstractinterpretation.jl:890
typeinf_local at ./compiler/abstractinterpretation.jl:1135
typeinf_nocycle at ./compiler/abstractinterpretation.jl:1191
typeinf at ./compiler/typeinfer.jl:14
typeinf_edge at ./compiler/typeinfer.jl:497
abstract_call_method at ./compiler/abstractinterpretation.jl:345
abstract_call_gf_by_type at ./compiler/abstractinterpretation.jl:85
abstract_call at ./compiler/abstractinterpretation.jl:776
abstract_eval_call at ./compiler/abstractinterpretation.jl:805
abstract_eval at ./compiler/abstractinterpretation.jl:890
typeinf_local at ./compiler/abstractinterpretation.jl:1135
typeinf_nocycle at ./compiler/abstractinterpretation.jl:1191
typeinf at ./compiler/typeinfer.jl:14
typeinf_edge at ./compiler/typeinfer.jl:497
abstract_call_method at ./compiler/abstractinterpretation.jl:345
abstract_call_gf_by_type at ./compiler/abstractinterpretation.jl:85
abstract_call at ./compiler/abstractinterpretation.jl:776
abstract_eval_call at ./compiler/abstractinterpretation.jl:805
abstract_eval at ./compiler/abstractinterpretation.jl:890
typeinf_local at ./compiler/abstractinterpretation.jl:1135
typeinf_nocycle at ./compiler/abstractinterpretation.jl:1191
typeinf at ./compiler/typeinfer.jl:14
typeinf_ext at ./compiler/typeinfer.jl:576
typeinf_ext at ./compiler/typeinfer.jl:613
jfptr_typeinf_ext_1.clone_1 at /Applications/Julia-1.1.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
jl_apply_generic at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:2219 [inlined]
jl_apply at /Users/osx/buildbot/slave/package_osx64/build/src/./julia.h:1571 [inlined]
jl_type_infer at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:277
jl_compile_method_internal at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1819
jl_fptr_trampoline at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1863
do_call at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:323
eval_stmt_value at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:362 [inlined]
eval_body at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:759
jl_interpret_toplevel_thunk_callback at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:885
Interpreter frame (ip: 0)
Core.CodeInfo(code=Array{Any, (2,)}[
  Expr(:call, :Foo, 1, 2, 3),
  Expr(:return, SSAValue(1))], codelocs=Array{Int32, (2,)}[1, 1], method_for_inference_limit_heuristics=nothing, ssavaluetypes=2, linetable=Array{Any, (1,)}[Core.LineInfoNode(mod=Main, method=Symbol("top-level scope"), file=:none, line=0, inlined_at=0)], ssaflags=Array{UInt8, (0,)}[], slotflags=Array{UInt8, (0,)}[], slotnames=Array{Any, (0,)}[], inferred=false, inlineable=false, propagate_inbounds=false, pure=false)jl_interpret_toplevel_thunk at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:894
jl_toplevel_eval_flex at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:764
jl_toplevel_eval at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:773 [inlined]
jl_toplevel_eval_in at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:793
eval at ./boot.jl:328
eval_user_input at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:85
macro expansion at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:117 [inlined]
#26 at ./task.jl:259
jl_apply at /Users/osx/buildbot/slave/package_osx64/build/src/./julia.h:1571 [inlined]
start_task at /Users/osx/buildbot/slave/package_osx64/build/src/task.c:572
Internal error: encountered unexpected error in runtime:
TypeError(func=:UnionAll, context="", expected=Type, got=3)
rec_backtrace at /Users/osx/buildbot/slave/package_osx64/build/src/stackwalk.c:94
record_backtrace at /Users/osx/buildbot/slave/package_osx64/build/src/task.c:217 [inlined]
jl_throw at /Users/osx/buildbot/slave/package_osx64/build/src/task.c:417
jl_type_error_rt at /Users/osx/buildbot/slave/package_osx64/build/src/rtutils.c:118
jl_type_error at /Users/osx/buildbot/slave/package_osx64/build/src/rtutils.c:125
jl_type_unionall at /Users/osx/buildbot/slave/package_osx64/build/src/jltypes.c:521
Type at ./boot.jl:353
rewrap_unionall at ./essentials.jl:209 [inlined]
fieldtype_tfunc at ./compiler/tfuncs.jl:877
jl_apply at /Users/osx/buildbot/slave/package_osx64/build/src/./julia.h:1571 [inlined]
jl_f__apply at /Users/osx/buildbot/slave/package_osx64/build/src/builtins.c:556
builtin_tfunction at ./compiler/tfuncs.jl:1286
builtin_tfunction at ./compiler/tfuncs.jl:1200 [inlined]
abstract_call at ./compiler/abstractinterpretation.jl:593
abstract_eval_call at ./compiler/abstractinterpretation.jl:805
abstract_eval at ./compiler/abstractinterpretation.jl:890
typeinf_local at ./compiler/abstractinterpretation.jl:1135
typeinf_nocycle at ./compiler/abstractinterpretation.jl:1191
typeinf at ./compiler/typeinfer.jl:14
typeinf_edge at ./compiler/typeinfer.jl:497
abstract_call_method at ./compiler/abstractinterpretation.jl:345
abstract_call_gf_by_type at ./compiler/abstractinterpretation.jl:85
abstract_call at ./compiler/abstractinterpretation.jl:776
abstract_eval_call at ./compiler/abstractinterpretation.jl:805
abstract_eval at ./compiler/abstractinterpretation.jl:890
typeinf_local at ./compiler/abstractinterpretation.jl:1135
typeinf_nocycle at ./compiler/abstractinterpretation.jl:1191
typeinf at ./compiler/typeinfer.jl:14
typeinf_ext at ./compiler/typeinfer.jl:576
typeinf_ext at ./compiler/typeinfer.jl:613
jfptr_typeinf_ext_1.clone_1 at /Applications/Julia-1.1.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
jl_apply_generic at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:2219 [inlined]
jl_apply at /Users/osx/buildbot/slave/package_osx64/build/src/./julia.h:1571 [inlined]
jl_type_infer at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:277
jl_compile_method_internal at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1819
jl_fptr_trampoline at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1863
Type at ./REPL[1]:3
jl_fptr_trampoline at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1864
do_call at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:323
eval_stmt_value at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:362 [inlined]
eval_body at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:759
jl_interpret_toplevel_thunk_callback at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:885
Interpreter frame (ip: 0)
Core.CodeInfo(code=Array{Any, (2,)}[
  Expr(:call, :Foo, 1, 2, 3),
  Expr(:return, SSAValue(1))], codelocs=Array{Int32, (2,)}[1, 1], method_for_inference_limit_heuristics=nothing, ssavaluetypes=2, linetable=Array{Any, (1,)}[Core.LineInfoNode(mod=Main, method=Symbol("top-level scope"), file=:none, line=0, inlined_at=0)], ssaflags=Array{UInt8, (0,)}[], slotflags=Array{UInt8, (0,)}[], slotnames=Array{Any, (0,)}[], inferred=false, inlineable=false, propagate_inbounds=false, pure=false)jl_interpret_toplevel_thunk at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:894
jl_toplevel_eval_flex at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:764
jl_toplevel_eval at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:773 [inlined]
jl_toplevel_eval_in at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:793
eval at ./boot.jl:328
eval_user_input at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:85
macro expansion at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:117 [inlined]
#26 at ./task.jl:259
jl_apply at /Users/osx/buildbot/slave/package_osx64/build/src/./julia.h:1571 [inlined]
start_task at /Users/osx/buildbot/slave/package_osx64/build/src/task.c:572
ERROR: TypeError: in UnionAll, expected Type, got Int64
Stacktrace:
 [1] tuple_type_head(::Type) at ./essentials.jl:175
 [2] convert(::Type{Tuple{Vararg{V,N} where N}}, ::Tuple) at ./essentials.jl:280
 [3] Foo(::Vararg{Any,N} where N) at ./REPL[1]:3
 [4] top-level scope at none:0

julia> versioninfo()
Julia Version 1.1.0
Commit 80516ca202 (2019-01-21 21:24 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin14.5.0)
  CPU: Intel(R) Core(TM) i7-3615QM CPU @ 2.30GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, ivybridge)
Environment:
  JULIA_EDITOR = subl

[Keno]

So I thought we could just disallow NTuple{<:Any, 3}, but unfortunately, (NTuple{T, 3} where T){3} is a valid type (the type Tuple{3,3,3} and moreover this is actually used in a few packages, so we can't really do anything here unless we completely disallow non-kinds in covariant position, but that's not something we could do until 2.0.

[Keno]

(we can still fix fieldtype to not error of course).

[StefanKarpinski]

Bump.

[brenhinkeller]

Still reproduces on 1.8.3 and 1.9.0-alpha1