Type does not equal itself?

[ChrisRackauckas]

From SciML/OrdinaryDiffEq.jl#737, https://travis-ci.org/JuliaDiffEq/OrdinaryDiffEq.jl/jobs/536089349#L808,

TypeError: in new, expected NTuple{49,Int64}, got NTuple{49,Int64}

Cannot reproduce locally, just on Travis. I am lost, because I used to believe that T == T for all types 😅 .

[iamed2]

This is called by https://github.com/JuliaArrays/StaticArrays.jl/blob/master/src/convert.jl#L4 so it might be some issue with Tuple{Vararg{Int64, 49}} vs NTuple{49, Int64}?

[JeffBezanson]

Tuple{Vararg{Int64, 49}} is === to NTuple{49, Int64}. This seems more like some kind of data corruption.

[StephenVavasis]

This may be unrelated, but I recently encountered an error message that a function expected a SparseMatrixCSC{Float64,Int} but received a SparseMatrixCSC{Float64,Int} instead. After some digging, I concluded that the JLD2 package was assigning the wrong type (even though the name was correct) to an object read from a JLD2 file. The workaround was to issue the commands using SparseArrays and import SparseArrays.SparseMatrixCSC before loading any modules (i.e., at the beginning of the script).

[timholy]

It is unrelated.

JLD2 will create a new type, with the same name, if it doesn't know the official one. That way you can at least load the data. JLD has addrequire, adding that to JLD2 might eliminate such problems, as long as the person saving the file remembers to use it.

[KristofferC]

Another case where something like this happened (PkgEval for 1.3-RC3):

history_recorder: Test Failed at /root/.julia/packages/POMDPSimulators/61Pgi/test/test_history_recorder.jl:145
  Expression: exception(exhist) !== nothing
   Evaluated: nothing !== nothing
Stacktrace:
 [1] top-level scope at /root/.julia/packages/POMDPSimulators/61Pgi/test/test_history_recorder.jl:145
 [2] include at ./boot.jl:328 [inlined]
 [3] include_relative(::Module, ::String) at ./loading.jl:1105
 [4] include(::Module, ::String) at ./Base.jl:31
 [5] include(::String) at ./client.jl:432
 [6] top-level scope at /root/.julia/packages/POMDPSimulators/61Pgi/test/runtests.jl:19
 [7] top-level scope at /workspace/srcdir/julia/usr/share/julia/stdlib/v1.3/Test/src/Test.jl:1107
 [8] top-level scope at /root/.julia/packages/POMDPSimulators/61Pgi/test/runtests.jl:19

[vtjnash]

Possibly fixed by #32605