getproperty doesn't satisfy the Tables.jl AbstractRow interface with Distributed

[StevenWhitaker]

I get the error mentioned in the title with the following example. I'm not sure if it's related to JuliaParallel/Dagger.jl#431, so I'm doing a separate issue.

Contents of mwe.jl:

using Distributed, DelimitedFiles
nworkers = 1
addprocs(nworkers - nprocs() + 1)

@everywhere using CSV, DTables, DataFrames

file = tempname() * ".csv"
writedlm(file, [1, 2])

# See issue JuliaParallel/Dagger.jl#431 for the purpose of this next line.
DTable(x -> CSV.File(x), [file]; tabletype = DataFrame)

remotecall_fetch(2, file) do f
    d = DTable(x -> CSV.File(x), [f]; tabletype = DataFrame)
    getproperty(d, Symbol("1"))
end

rm(file)

Results:

julia> include("mwe.jl")
Error in eager scheduler:
On worker 2:
ArgumentError: 'Tuple{Bool, Tables.Schema{(Symbol("1"),), Tuple{Int64}}}' iterates 'Bool' values, which doesn't satisfy the Tables.jl `AbstractRow` interface
Stacktrace:
  [1] invalidtable
    @ ~/.julia/packages/Tables/AcRIE/src/tofromdatavalues.jl:41
  [2] iterate
    @ ~/.julia/packages/Tables/AcRIE/src/tofromdatavalues.jl:47 [inlined]
  [3] buildcolumns
    @ ~/.julia/packages/Tables/AcRIE/src/fallbacks.jl:209 [inlined]
  [4] _columns
    @ ~/.julia/packages/Tables/AcRIE/src/fallbacks.jl:274 [inlined]
  [5] columns
    @ ~/.julia/packages/Tables/AcRIE/src/fallbacks.jl:258 [inlined]
  [6] getcolumn_chunk
    @ ~/.julia/packages/DTables/bA4g3/src/table/dtable_column.jl:12
  [7] JuliaParallel/DTables.jl#36
    @ ~/.julia/packages/DTables/bA4g3/src/table/dtable_column.jl:23
  [8] #invokelatest#2
    @ ./essentials.jl:819 [inlined]
  [9] invokelatest
    @ ./essentials.jl:816 [inlined]
 [10] JuliaParallel/DTables.jl#43
    @ ~/.julia/packages/Dagger/xGAvM/src/processor.jl:162
Stacktrace:
  [1] wait
    @ ./task.jl:349 [inlined]
  [2] fetch
    @ ./task.jl:369 [inlined]
  [3] #execute!#42
    @ ~/.julia/packages/Dagger/xGAvM/src/processor.jl:172
  [4] execute!
    @ ~/.julia/packages/Dagger/xGAvM/src/processor.jl:157
  [5] #156
    @ ~/.julia/packages/Dagger/xGAvM/src/sch/Sch.jl:1552 [inlined]
  [6] JuliaParallel/DTables.jl#21
    @ ~/.julia/packages/Dagger/xGAvM/src/options.jl:17
  [7] with_logstate
    @ ./logging.jl:514
  [8] with_logger
    @ ./logging.jl:626 [inlined]
  [9] with_task_ctxvars
    @ ~/.julia/packages/ContextVariablesX/ujYRr/src/payloadlogger.jl:16
 [10] with_context
    @ ~/.julia/packages/ContextVariablesX/ujYRr/src/ContextVariablesX.jl:336
 [11] with_options
    @ ~/.julia/packages/Dagger/xGAvM/src/options.jl:16
 [12] do_task
    @ ~/.julia/packages/Dagger/xGAvM/src/sch/Sch.jl:1550
 [13] macro expansion
    @ ~/.julia/packages/Dagger/xGAvM/src/sch/Sch.jl:1244 [inlined]
 [14] #130
    @ ./task.jl:134
Stacktrace:
 [1] (::Dagger.Sch.var"#91#92"{Dagger.Context, Dagger.Sch.ComputeState, Dagger.OSProc, NamedTuple{(:time_pressure, :storage_pressure, :storage_capacity, :loadavg, :threadtime, :gc_allocd, :transfer_rate), Tuple{UInt64, UInt64, UInt64, Tuple{Float64, Float64, Float64}, UInt64, Int64, UInt64}}, RemoteException, Int64, Dagger.ThreadProc, Int64})()
   @ Dagger.Sch ~/.julia/packages/Dagger/xGAvM/src/sch/Sch.jl:541
 [2] lock(f::Dagger.Sch.var"#91#92"{Dagger.Context, Dagger.Sch.ComputeState, Dagger.OSProc, NamedTuple{(:time_pressure, :storage_pressure, :storage_capacity, :loadavg, :threadtime, :gc_allocd, :transfer_rate), Tuple{UInt64, UInt64, UInt64, Tuple{Float64, Float64, Float64}, UInt64, Int64, UInt64}}, RemoteException, Int64, Dagger.ThreadProc, Int64}, l::ReentrantLock)
   @ Base ./lock.jl:229
 [3] scheduler_run(ctx::Dagger.Context, state::Dagger.Sch.ComputeState, d::Dagger.Thunk, options::Dagger.Sch.SchedulerOptions)
   @ Dagger.Sch ~/.julia/packages/Dagger/xGAvM/src/sch/Sch.jl:525
 [4] compute_dag(ctx::Dagger.Context, d::Dagger.Thunk; options::Dagger.Sch.SchedulerOptions)
   @ Dagger.Sch ~/.julia/packages/Dagger/xGAvM/src/sch/Sch.jl:449
 [5] compute_dag
   @ ~/.julia/packages/Dagger/xGAvM/src/sch/Sch.jl:414 [inlined]
 [6] compute(ctx::Dagger.Context, d::Dagger.Thunk; options::Dagger.Sch.SchedulerOptions)
   @ Dagger ~/.julia/packages/Dagger/xGAvM/src/compute.jl:23
 [7] compute
   @ ~/.julia/packages/Dagger/xGAvM/src/compute.jl:22 [inlined]
 [8] macro expansion
   @ ~/.julia/packages/Dagger/xGAvM/src/sch/eager.jl:28 [inlined]
 [9] (::Dagger.Sch.var"#50#51"{Dagger.Context})()
   @ Dagger.Sch ./threadingconstructs.jl:410
ERROR: LoadError: On worker 2:
SchedulingException (Scheduler exited)
Stacktrace:
  [1] #fetch#70
    @ ~/.julia/packages/Dagger/xGAvM/src/eager_thunk.jl:16
  [2] fetch
    @ ~/.julia/packages/Dagger/xGAvM/src/eager_thunk.jl:11 [inlined]
  [3] #fetch#75
    @ ~/.julia/packages/Dagger/xGAvM/src/eager_thunk.jl:58 [inlined]
  [4] fetch
    @ ~/.julia/packages/Dagger/xGAvM/src/eager_thunk.jl:54 [inlined]
  [5] DTableColumn
    @ ~/.julia/packages/DTables/bA4g3/src/table/dtable_column.jl:21
  [6] DTableColumn
    @ ~/.julia/packages/DTables/bA4g3/src/table/dtable_column.jl:35
  [7] DTableColumn
    @ ~/.julia/packages/DTables/bA4g3/src/table/dtable_column.jl:37 [inlined]
  [8] getproperty
    @ ~/.julia/packages/DTables/bA4g3/src/table/dtable.jl:291 [inlined]
  [9] JuliaParallel/DTables.jl#7
    @ ~/tmp/mwe.jl:15
 [10] #invokelatest#2
    @ ./essentials.jl:819
 [11] invokelatest
    @ ./essentials.jl:816
 [12] #110
    @ ~/programs/julia/julia-1.9.3/share/julia/stdlib/v1.9/Distributed/src/process_messages.jl:285
 [13] run_work_thunk
    @ ~/programs/julia/julia-1.9.3/share/julia/stdlib/v1.9/Distributed/src/process_messages.jl:70
 [14] macro expansion
    @ ~/programs/julia/julia-1.9.3/share/julia/stdlib/v1.9/Distributed/src/process_messages.jl:285 [inlined]
 [15] #109
    @ ./task.jl:514
Stacktrace:
 [1] remotecall_fetch(f::Function, w::Distributed.Worker, args::String; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
   @ Distributed ~/programs/julia/julia-1.9.3/share/julia/stdlib/v1.9/Distributed/src/remotecall.jl:465
 [2] remotecall_fetch(f::Function, w::Distributed.Worker, args::String)
   @ Distributed ~/programs/julia/julia-1.9.3/share/julia/stdlib/v1.9/Distributed/src/remotecall.jl:454
 [3] #remotecall_fetch#162
   @ ~/programs/julia/julia-1.9.3/share/julia/stdlib/v1.9/Distributed/src/remotecall.jl:492 [inlined]
 [4] remotecall_fetch(f::Function, id::Int64, args::String)
   @ Distributed ~/programs/julia/julia-1.9.3/share/julia/stdlib/v1.9/Distributed/src/remotecall.jl:492
 [5] top-level scope
   @ ~/tmp/mwe.jl:13
 [6] include(fname::String)
   @ Base.MainInclude ./client.jl:478
 [7] top-level scope
   @ REPL[1]:1
in expression starting at /home/steven/tmp/mwe.jl:13

(tmp) pkg> st
Status `~/tmp/Project.toml`
  [336ed68f] CSV v0.10.11
  [20c56dc6] DTables v0.4.1
  [a93c6f00] DataFrames v1.6.1
  [8bb1440f] DelimitedFiles v1.9.1
  [8ba89e20] Distributed

Note that the above error message only shows if I change line 543 in src/sch/Sch.jl in Dagger.jl from thunk_failed = true to throw(res). (I filed JuliaParallel/Dagger.jl#430 about this.)

Let me know if I'm missing anything or if I'm doing something wrong.

[jpsamaroo]

This now works for me with Dagger 0.18.3 (just released); it appears it was the Dagger bug that was fixed by JuliaParallel/Dagger.jl#436. Thanks for all the issue reports!