`@deprecate` usage invalid on Julia <=1.7

[MilesCranmer]

This is breaking downstream compatibility with older Julia versions: if I install RecursiveArrayTools in a fresh environment:

julia +1.6 --startup-file=no -e 'using Pkg; pkg"activate --temp"; pkg"add RecursiveArrayTools"; pkg"precompile"'

I get this error:

Precompiling project...
  ✗ RecursiveArrayTools
  0 dependencies successfully precompiled in 2 seconds (16 already precompiled)
  1 dependency errored. To see a full report either run `import Pkg; Pkg.precompile()` or load the package
Precompiling project...
  ✗ RecursiveArrayTools
  0 dependencies successfully precompiled in 1 seconds (16 already precompiled)

ERROR: The following 1 direct dependency failed to precompile:

RecursiveArrayTools [731186ca-8d62-57ce-b412-fbd966d074cd]

Failed to precompile RecursiveArrayTools [731186ca-8d62-57ce-b412-fbd966d074cd] to /Users/mcranmer/.julia/compiled/v1.6/RecursiveArrayTools/jl_RqK3gX.
ERROR: LoadError: LoadError: LoadError: invalid usage of @deprecate
Stacktrace:
  [1] error(s::String)
    @ Base ./error.jl:33
  [2] var"@deprecate"(__source__::LineNumberNode, __module__::Module, old::Any, new::Any, ex::Any)
    @ Base ./deprecated.jl:62
  [3] include(mod::Module, _path::String)
    @ Base ./Base.jl:384
  [4] include(x::String)
    @ RecursiveArrayTools ~/.julia/packages/RecursiveArrayTools/1yY5f/src/RecursiveArrayTools.jl:5
  [5] top-level scope
    @ ~/.julia/packages/RecursiveArrayTools/1yY5f/src/RecursiveArrayTools.jl:20
  [6] include
    @ ./Base.jl:384 [inlined]
  [7] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{String}, dl_load_path::Vector{String}, load_path::Vector{String}, concrete_deps::Vector{Pair{Base.PkgId, UInt64}}, source::Nothing)
    @ Base ./loading.jl:1235
  [8] top-level scope
    @ none:1
  [9] eval
    @ ./boot.jl:360 [inlined]
 [10] eval(x::Expr)
    @ Base.MainInclude ./client.jl:446
 [11] top-level scope
    @ none:1
in expression starting at /Users/mcranmer/.julia/packages/RecursiveArrayTools/1yY5f/src/vector_of_array.jl:224
in expression starting at /Users/mcranmer/.julia/packages/RecursiveArrayTools/1yY5f/src/vector_of_array.jl:224
in expression starting at /Users/mcranmer/.julia/packages/RecursiveArrayTools/1yY5f/src/RecursiveArrayTools.jl:2
Stacktrace:
 [1] pkgerror(msg::String)
   @ Pkg.Types /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Types.jl:55
 [2] precompile(ctx::Pkg.Types.Context; internal_call::Bool, strict::Bool, warn_loaded::Bool, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
   @ Pkg.API /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:1265
 [3] precompile
   @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:921 [inlined]
 [4] #precompile#196
   @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:919 [inlined]
 [5] precompile()
   @ Pkg.API /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:919
 [6] do_cmd!(command::Pkg.REPLMode.Command, repl::Pkg.REPLMode.MiniREPL)
   @ Pkg.REPLMode /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/REPLMode/REPLMode.jl:405
 [7] do_cmd(repl::Pkg.REPLMode.MiniREPL, input::String; do_rethrow::Bool)
   @ Pkg.REPLMode /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/REPLMode/REPLMode.jl:386
 [8] top-level scope
   @ none:1

[MilesCranmer]

@ChrisRackauckas @AayushSabharwal sorry to bother you about this but this error is currently breaking tons of downstream packages on older Julia versions – it's impossible to install any package that indirectly depends on RecursiveArrayTools.jl unless you force install an earlier version.

If the idea is to not support Julia 1.6 could this be set this in the Project.toml? Currently it says 1.6 so all older Julia versions are getting hit by it.

I think maybe the reason this wasn't noticed is that the CI has a blind spot and isn't actually testing older Julia:

https://github.com/SciML/RecursiveArrayTools.jl/actions/runs/7177904059/job/19545138534#step:6:22

[ Warning: julia version requirement for project not satisfied
julia version requirement for package `DiffEqBase [2b5f629d]` not satisfied
[ Warning: julia version requirement for project not satisfied
julia version requirement for package `DiffEqBase [2b5f629d]` not satisfied
[ Warning: julia version requirement for project not satisfied
julia version requirement for package `DiffEqBase [2b5f629d]` not satisfied
[ Warning: julia version requirement for project not satisfied
julia version requirement for package `DiffEqBase [2b5f629d]` not satisfied
┌ Info: Not compatible with this release. No problem.
└   exception = empty intersection between RecursiveArrayTools@3.0.0 and project compatibility 2

which might be why this wasn't caught.

[AayushSabharwal]

Thanks for pointing that out. I think we should bump the julia compat to at least 1.8 in this case, if not 1.9. I'll address this in #298

CI didn't notice this because CI couldn't run until several other packages were tagged. That is the reason for #298 (to rerun CI and weed out issues). 1.6 doesn't resolve there due to incompatibilities with other packages, so it makes sense for this package to update to 1.9 anyway

[MilesCranmer]

@AayushSabharwal I see. I guess you will need to submit a patch to the Julia registry to recall the earlier version, because 3.0.0 was already registered for 1.6?

[AayushSabharwal]

I guess so

[MilesCranmer]

I guess submit a PR on https://github.com/JuliaRegistries/General/blob/e3e462fe3a68fc3c105053e2d45722fb04545634/R/RecursiveArrayTools/Compat.toml#L164-L166

with the diff

  [3]
  Statistics = "1"
  SymbolicIndexingInterface = "0.3"
+ julia = "1.8.0-1"

?

[MilesCranmer]

Or even 1.9 if you aren't testing on 1.8? (so there aren't other issues)

[ChrisRackauckas]

with the diff

No, general shouldn't be modified like that. Instead, bump the lower bound to v1.9 and then yank the existing v3's and put a new v3 out there.

[MilesCranmer]

I see, thanks for the tip. And thanks for quickly addressing this; much appreciated!