Error on julia 1.6.0 nightly when reading csv

[dwinkler1]

I am getting the following error when reading a csv file:

julia> CSV.File("test/testfiles/mtcars.csv")
ERROR: MethodError: no method matching typesubtract(::Type{Union{}}, ::Type{Int64})
Closest candidates are:
  typesubtract(::Any, ::Any, ::Int64) at compiler/typeutils.jl:66
Stacktrace:
  [1] ts(T::Type, S::Type)
    @ CSV ~/.julia/packages/CSV/MKemC/src/utils.jl:214
  [2] nonstandardtype(T::Type)
    @ CSV ~/.julia/packages/CSV/MKemC/src/utils.jl:217
  [3] (::CSV.var"#17#23")(T::Type)
    @ CSV ./none:0
  [4] iterate(::Base.Iterators.Filter{CSV.var"#17#23", Vector{Type}})
    @ Base.Iterators ./iterators.jl:451
  [5] iterate
    @ ./generator.jl:44 [inlined]
  [6] Header
    @ ~/.julia/packages/CSV/MKemC/src/header.jl:232 [inlined]
  [7] CSV.File(source::String; header::Int64, normalizenames::Bool, datarow::Int64, skipto::Nothing, footerskip::Int64, transpose::Bool, comment::Nothing, use_mmap::Nothing, ignoreemptylines::Bool, select::Nothing, drop::Nothing, missingstrings::Vector{String}, missingstring::String, delim::Nothing, ignorerepeated::Bool, quotechar::Char, openquotechar::Nothing, closequotechar::Nothing, escapechar::Char, dateformat::Nothing, dateformats::Nothing, decimal::UInt8, truestrings::Vector{String}, falsestrings::Vector{String}, type::Nothing, types::Nothing, typemap::Dict{Type, Type}, categorical::Nothing, pool::Float64, lazystrings::Bool, strict::Bool, silencewarnings::Bool, debug::Bool, parsingdebug::Bool, kw::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ CSV ~/.julia/packages/CSV/MKemC/src/file.jl:216
  [8] CSV.File(source::String)
    @ CSV ~/.julia/packages/CSV/MKemC/src/file.jl:216
  [9] top-level scope
    @ REPL[13]:1
 [10] eval
    @ ./boot.jl:360 [inlined]

julia> versioninfo()
Julia Version 1.6.0-DEV.1276
Commit 2655a3ad5d (2020-10-18 19:49 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i5-8265U CPU @ 1.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-11.0.0 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 8
  JULIA_EDITOR = "/usr/share/code/code"

Any suggestions what I am doing wrong? The same file works on julia 1.5

[quinnj]

Please checkout CSV.jl master when working with unreleased Julia version. It's been fixed there

[dwinkler1]

Sorry! Thanks for the quick reply!

[quinnj]

No problem; I usually try to get quick fixes like that out, but I'm actually in the middle of just having put a new feature in (#754 ) and actively experimenting with solutions to another bigger issue (#727), along with a another new feature I want to get in before the next release, so yeah, just kind of caught in the middle here.