SVM Errors With Grid Search

@ablaom - I tried your code with the make_blobs() and ScikitLearn’s SVM and am getting the same error as before:

Error
┌ Error: Problem fitting the machine Machine{Resampler{CV},…}. 
└ @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:533
[ Info: Running type checks... 
[ Info: Type checks okay. 
┌ Error: Problem fitting the machine Machine{DeterministicTunedModel{Grid,…},…}. 
└ @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:533
[ Info: Running type checks... 
[ Info: Type checks okay. 
ERROR: LoadError: TypeError: in CategoricalValue, in T, expected T<:Union{AbstractChar, AbstractString, Number}, got Type{Any}
Stacktrace:
   [1] argtypes_to_type
     @ ./compiler/typeutils.jl:50 [inlined]
   [2] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1032
   [3] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
   [4] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
   [5] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
   [6] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
   [7] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
   [8] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
   [9] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
  [10] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
  [11] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
  [12] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
  [13] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1033
--- the last 11 lines are repeated 1 more time ---
  [25] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
  [26] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
  [27] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
  [28] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
  [29] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
  [30] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
  [31] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
  [32] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
  [33] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
  [34] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
  [35] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1054
  [36] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
  [37] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
  [38] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
  [39] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
  [40] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
  [41] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
  [42] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
  [43] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
  [44] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
  [45] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Nothing, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1033
  [46] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Nothing, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
  [47] abstract_apply(interp::Core.Compiler.NativeInterpreter, itft::Any, aft::Any, aargtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:738
  [48] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:952
  [49] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
  [50] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
  [51] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
  [52] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
  [53] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
  [54] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
  [55] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
  [56] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
  [57] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
  [58] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
  [59] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1033
  [60] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
  [61] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
  [62] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
  [63] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
  [64] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
  [65] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
  [66] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
  [67] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
  [68] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
  [69] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
  [70] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1054
  [71] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
  [72] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
  [73] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
  [74] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
  [75] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
  [76] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
  [77] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
  [78] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
  [79] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
  [80] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1033
  [81] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
--- the last 11 lines are repeated 1 more time ---
  [93] abstract_apply(interp::Core.Compiler.NativeInterpreter, itft::Any, aft::Any, aargtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:738
  [94] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:952
  [95] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
  [96] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
  [97] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
  [98] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
  [99] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
 [100] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
 [101] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
 [102] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
 [103] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
 [104] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
 [105] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1033
--- the last 11 lines are repeated 1 more time ---
 [117] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
 [118] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
 [119] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
 [120] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
 [121] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
 [122] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
 [123] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
 [124] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
 [125] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
 [126] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
 [127] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1054
 [128] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
 [129] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
 [130] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1462
 [131] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
 [132] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
 [133] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
 [134] typeinf_edge(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector, caller::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:806
 [135] abstract_call_method(interp::Core.Compiler.NativeInterpreter, method::Method, sig::Any, sparams::Core.SimpleVector, hardlimit::Bool, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:490
 [136] abstract_call_gf_by_type(interp::Core.Compiler.NativeInterpreter, f::Any, argtypes::Vector{Any}, atype::Any, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:143
 [137] abstract_call_known(interp::Core.Compiler.NativeInterpreter, f::Any, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1033
 [138] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState, max_methods::Int64)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1056
 [139] abstract_call(interp::Core.Compiler.NativeInterpreter, fargs::Vector{Any}, argtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1040
 [140] abstract_eval_statement(interp::Core.Compiler.NativeInterpreter, e::Any, vtypes::Vector{Any}, sv::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1167
 [141] typeinf_local(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1447
 [142] typeinf_nocycle(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/abstractinterpretation.jl:1520
 [143] _typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:214
 [144] typeinf(interp::Core.Compiler.NativeInterpreter, frame::Core.Compiler.InferenceState)
     @ Core.Compiler ./compiler/typeinfer.jl:209
 [145] typeinf
     @ ./compiler/typeinfer.jl:8 [inlined]
 [146] typeinf_type(interp::Core.Compiler.NativeInterpreter, method::Method, atypes::Any, sparams::Core.SimpleVector)
     @ Core.Compiler ./compiler/typeinfer.jl:914
 [147] return_type(interp::Core.Compiler.NativeInterpreter, f::Any, t::Any)
     @ Core.Compiler ./compiler/typeinfer.jl:963
 [148] return_type(f::Any, t::Any, world::UInt64)
     @ Core.Compiler ./compiler/typeinfer.jl:950
 [149] return_type(f::Any, t::Any)
     @ Core.Compiler ./compiler/typeinfer.jl:947
 [150] macro expansion
     @ ./array.jl:652 [inlined]
 [151] dict_with_eltype(DT_apply::F, kv::Base.Generator, t::Any) where F
     @ Base ./abstractdict.jl:541
 [152] Dict(kv::Any)
     @ Base ./dict.jl:129
 [153] (::MLJBase.var"#fit_and_extract_on_fold#299")(mach::Any, k::Any)
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/resampling.jl:1086
 [154] (::MLJBase.var"#276#277")(k::Any)
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/resampling.jl:927
 [155] mapreduce_impl(f::Any, op::Any, A::Union{Base.AbstractBroadcasted, AbstractArray}, ifirst::Integer, ilast::Integer, blksize::Int64)
     @ Base ./reduce.jl:242
 [156] mapreduce_impl(f::Function, op::Function, A::UnitRange{Int64}, ifirst::Int64, ilast::Int64)
     @ Base ./reduce.jl:257
 [157] _mapreduce(f::Any, op::Any, #unused#::IndexLinear, A::Union{Base.AbstractBroadcasted, AbstractArray})
     @ Base ./reduce.jl:415
 [158] _mapreduce_dim(f::Function, op::Function, #unused#::Base._InitialValue, A::UnitRange{Int64}, #unused#::Colon)
     @ Base ./reducedim.jl:318
 [159] #mapreduce#672
     @ ./reducedim.jl:310 [inlined]
 [160] mapreduce(f::Function, op::Function, A::UnitRange{Int64})
     @ Base ./reducedim.jl:310
 [161] _evaluate!(func::Any, mach::Any, #unused#::CPU1, nfolds::Any, verbosity::Any)
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/resampling.jl:926
 [162] evaluate!(mach::Machine{MLJScikitLearnInterface.SVMClassifier, true}, resampling::Vector{Tuple{Vector{Int64}, UnitRange{Int64}}}, weights::Nothing, class_weights::Nothing, rows::Nothing, verbosity::Int64, repeats::Int64, measures::Vector{Accuracy}, operations::Vector{typeof(predict)}, acceleration::CPU1{Nothing}, force::Bool)
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/resampling.jl:1121
 [163] evaluate!(::Machine{MLJScikitLearnInterface.SVMClassifier, true}, ::CV, ::Nothing, ::Nothing, ::Nothing, ::Int64, ::Int64, ::Vector{Accuracy}, ::Vector{typeof(predict)}, ::CPU1{Nothing}, ::Bool)
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/resampling.jl:1188
 [164] fit(::Resampler{CV}, ::Int64, ::Tables.MatrixTable{Matrix{Float64}}, ::CategoricalVector{Int64, UInt32, Int64, CategoricalValue{Int64, UInt32}, Union{}})
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/resampling.jl:1332
 [165] fit_only!(mach::Machine{Resampler{CV}, false}; rows::Nothing, verbosity::Int64, force::Bool)
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:531
 [166] #fit!#103
     @ ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:598 [inlined]
 [167] event!(metamodel::MLJScikitLearnInterface.SVMClassifier, resampling_machine::Machine{Resampler{CV}, false}, verbosity::Int64, tuning::Grid, history::Nothing, state::NamedTuple{(:models, :fields, :parameter_scales, :models_delivered), Tuple{Vector{MLJScikitLearnInterface.SVMClassifier}, Vector{Symbol}, Vector{Symbol}, Bool}})
     @ MLJTuning ~/.julia/packages/MLJTuning/bjRHJ/src/tuned_models.jl:390
 [168] #35
     @ ~/.julia/packages/MLJTuning/bjRHJ/src/tuned_models.jl:428 [inlined]
 [169] iterate
     @ ./generator.jl:47 [inlined]
 [170] _collect(c::Vector{MLJScikitLearnInterface.SVMClassifier}, itr::Base.Generator{Vector{MLJScikitLearnInterface.SVMClassifier}, MLJTuning.var"#35#36"{Machine{Resampler{CV}, false}, Int64, Grid, Nothing, NamedTuple{(:models, :fields, :parameter_scales, :models_delivered), Tuple{Vector{MLJScikitLearnInterface.SVMClassifier}, Vector{Symbol}, Vector{Symbol}, Bool}}, ProgressMeter.Progress}}, #unused#::Base.EltypeUnknown, isz::Base.HasShape{1})
     @ Base ./array.jl:691
 [171] collect_similar
     @ ./array.jl:606 [inlined]
 [172] map
     @ ./abstractarray.jl:2294 [inlined]
 [173] assemble_events!(metamodels::Vector{MLJScikitLearnInterface.SVMClassifier}, resampling_machine::Machine{Resampler{CV}, false}, verbosity::Int64, tuning::Grid, history::Nothing, state::NamedTuple{(:models, :fields, :parameter_scales, :models_delivered), Tuple{Vector{MLJScikitLearnInterface.SVMClassifier}, Vector{Symbol}, Vector{Symbol}, Bool}}, acceleration::CPU1{Nothing})
     @ MLJTuning ~/.julia/packages/MLJTuning/bjRHJ/src/tuned_models.jl:427
 [174] build!(history::Nothing, n::Int64, tuning::Grid, model::MLJScikitLearnInterface.SVMClassifier, model_buffer::Channel{Any}, state::NamedTuple{(:models, :fields, :parameter_scales, :models_delivered), Tuple{Vector{MLJScikitLearnInterface.SVMClassifier}, Vector{Symbol}, Vector{Symbol}, Bool}}, verbosity::Int64, acceleration::CPU1{Nothing}, resampling_machine::Machine{Resampler{CV}, false})
     @ MLJTuning ~/.julia/packages/MLJTuning/bjRHJ/src/tuned_models.jl:620
 [175] fit(::MLJTuning.DeterministicTunedModel{Grid, MLJScikitLearnInterface.SVMClassifier}, ::Int64, ::Tables.MatrixTable{Matrix{Float64}}, ::CategoricalVector{Int64, UInt32, Int64, CategoricalValue{Int64, UInt32}, Union{}})
     @ MLJTuning ~/.julia/packages/MLJTuning/bjRHJ/src/tuned_models.jl:699
 [176] fit_only!(mach::Machine{MLJTuning.DeterministicTunedModel{Grid, MLJScikitLearnInterface.SVMClassifier}, true}; rows::Nothing, verbosity::Int64, force::Bool)
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:531
 [177] fit_only!
     @ ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:484 [inlined]
 [178] #fit!#103
     @ ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:598 [inlined]
 [179] fit!(mach::Machine{MLJTuning.DeterministicTunedModel{Grid, MLJScikitLearnInterface.SVMClassifier}, true})
     @ MLJBase ~/.julia/packages/MLJBase/u6vLz/src/machines.jl:596
Code
SVMClassifier = @load SVMClassifier pkg=ScikitLearn
svm_model = SVMClassifier()

r_svm = range(svm_model, :C, values=[0.25, 0.5, 1])
self_tuning_svm = TunedModel(model=svm_model,
                             resampling=CV(nfolds=10),
                             repeats=5,
                             tuning=Grid(),
                             range=r_svm,
                             measure=accuracy)

X, y_svm = make_blobs();

svm = machine(self_tuning_svm, X, y_svm)
MLJ.fit!(svm)

SVM fitting works fine with LIBSVM. Code is as follows:

SVMClassifier = @load SVC pkg=LIBSVM
svm_model = SVMClassifier()

r_svm = range(svm_model, :cost, values=[0.25, 0.5, 1])
self_tuning_svm = TunedModel(model=svm_model,
                             resampling=CV(nfolds=10),
                             repeats=5,
                             tuning=Grid(),
                             range=r_svm,
                             measure=accuracy)

X, y_svm = make_blobs();

svm = machine(self_tuning_svm, X, y_svm)
MLJ.fit!(svm)