martinholters
commented
4 years ago It's this assertion that is triggered: https://github.com/JuliaLang/julia/blob/6cd329c371c1db3d9876bc337e82e274e50420e8/base/compiler/typelimits.jl#L23 (And then it errors because it can't format it's message, which is unfortunate, because it makes it a bit harder to pinpoint the problem.)
The situation that leads to the assertion being triggered is this:
julia> t = Tuple{typeof(Hecke.ideal), Hecke.NfRelOrd{T, S, U}, U, U, S, S, Bool} where U where S<:(Hecke.NfRelOrdIdl{T, S, U} where U where S where T) where T
Tuple{typeof(ideal),Hecke.NfRelOrd{T,S,U},U,U,S,S,Bool} where U where S<:(Hecke.NfRelOrdIdl{T,S,U} where U where S where T) where T
julia> compare = Tuple{typeof(Hecke.ideal), Hecke.NfRelOrd{T, S, U}, U, U, S, S, Bool} where U where S where T
Tuple{typeof(ideal),Hecke.NfRelOrd{T,S,U},U,U,S,S,Bool} where U where S where T
julia> source = Core.svec() # more complicated in reality, but irrelevant
svec()
julia> r = Core.Compiler._limit_type_size(t, compare, source, 1, 8)
Tuple{typeof(ideal),Hecke.NfRelOrd,U,U,Hecke.NfRelOrdIdl,Hecke.NfRelOrdIdl,Bool} where U
julia> t <: r
falseThe problem here is that U is subject to the diagonal rule in r, but it isn't in t.
rfourquet
vtjnash
rikhuijzer
We have run into an error in the Julia type inference (see https://github.com/oscar-system/Oscar.jl/issues/104 for the original issue, for which we since implemented a workaround in https://github.com/oscar-system/Oscar.jl/pull/110). The issue happens in Julia 1.4.2 and also 1.5, but was fixed "by accident" (?) on the Julia master branch by PR #36200
To reproduce this, install
Oscarbut in a revision before the fix. So:Then there are several ways to trigger an issue. For example, this input
results in this:
and then
Or run the full test suite: