Pkg.test(force_latest_compatible_version=true) errors with unregistered dependencies trying to reduce over an empty collection #3684
Description
If a project contains unregistered dependencies and is tested with Pkg.test(force_latest_compatible_version=true), an error is thrown in the call to maximum at
Line 2602 in 4b8e390
compatible_versions is empty.
This gives you a stacktrace like below. Should this case be tested for and a more helpful error be thrown instead?
Testing Tester
ERROR: LoadError: MethodError: reducing over an empty collection is not allowed; consider supplying `init` to the reducer
Stacktrace:
[1] reduce_empty(op::Base.BottomRF{typeof(max)}, #unused#::Type{VersionNumber})
@ Base ./reduce.jl:355
[2] reduce_empty_iter
@ ./reduce.jl:379 [inlined]
[3] reduce_empty_iter
@ ./reduce.jl:378 [inlined]
[4] foldl_impl
@ ./reduce.jl:49 [inlined]
[5] mapfoldl_impl
@ ./reduce.jl:44 [inlined]
[6] #mapfoldl#288
@ ./reduce.jl:170 [inlined]
[7] mapfoldl
@ ./reduce.jl:170 [inlined]
[8] #mapreduce#292
@ ./reduce.jl:302 [inlined]
[9] mapreduce
@ ./reduce.jl:302 [inlined]
[10] #maximum#302
@ ./reduce.jl:759 [inlined]
[11] maximum
@ ./reduce.jl:759 [inlined]
[12] get_latest_compatible_version
@ /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:2596 [inlined]
[13] apply_force_latest_compatible_version!(ctx::Pkg.Types.Context, dep::NamedTuple{(:name, :uuid), Tuple{String, Base.UUID}}; target_name::String, allow_earlier_backwards_compatible_versions::Bool)
@ Pkg.Operations /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:2564
[14] apply_force_latest_compatible_version!
@ /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:2548 [inlined]
[15] apply_force_latest_compatible_version!(ctx::Pkg.Types.Context; target_name::String, allow_earlier_backwards_compatible_versions::Bool)
@ Pkg.Operations /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:2537
[16] apply_force_latest_compatible_version!
@ /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:2530 [inlined]
[17] (::Pkg.Operations.var"#117#122"{String, Bool, Bool, Bool, Pkg.Operations.var"#130#134"{Bool, Cmd, Cmd, Nothing, Pkg.Types.Context, Vector{Tuple{String, Base.Process}}, String, Pkg.Types.PackageSpec}, Pkg.Types.PackageSpec})()
@ Pkg.Operations /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:1795
[18] with_temp_env(fn::Pkg.Operations.var"#117#122"{String, Bool, Bool, Bool, Pkg.Operations.var"#130#134"{Bool, Cmd, Cmd, Nothing, Pkg.Types.Context, Vector{Tuple{String, Base.Process}}, String, Pkg.Types.PackageSpec}, Pkg.Types.PackageSpec}, temp_env::String)
@ Pkg.Operations /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:1701
[19] (::Pkg.Operations.var"#115#120"{Dict{String, Any}, Bool, Bool, Bool, Pkg.Operations.var"#130#134"{Bool, Cmd, Cmd, Nothing, Pkg.Types.Context, Vector{Tuple{String, Base.Process}}, String, Pkg.Types.PackageSpec}, Pkg.Types.Context, Pkg.Types.PackageSpec, String, Pkg.Types.Project, String})(tmp::String)
@ Pkg.Operations /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:1790
[20] mktempdir(fn::Pkg.Operations.var"#115#120"{Dict{String, Any}, Bool, Bool, Bool, Pkg.Operations.var"#130#134"{Bool, Cmd, Cmd, Nothing, Pkg.Types.Context, Vector{Tuple{String, Base.Process}}, String, Pkg.Types.PackageSpec}, Pkg.Types.Context, Pkg.Types.PackageSpec, String, Pkg.Types.Project, String}, parent::String; prefix::String)
@ Base.Filesystem ./file.jl:760
[21] mktempdir(fn::Function, parent::String)
@ Base.Filesystem ./file.jl:756
[22] mktempdir
@ ./file.jl:756 [inlined]
[23] sandbox(fn::Function, ctx::Pkg.Types.Context, target::Pkg.Types.PackageSpec, target_path::String, sandbox_path::String, sandbox_project_override::Pkg.Types.Project; preferences::Dict{String, Any}, force_latest_compatible_version::Bool, allow_earlier_backwards_compatible_versions::Bool, allow_reresolve::Bool)
@ Pkg.Operations /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:1748
[24] test(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}; coverage::Bool, julia_args::Cmd, test_args::Cmd, test_fn::Nothing, force_latest_compatible_version::Bool, allow_earlier_backwards_compatible_versions::Bool, allow_reresolve::Bool)
@ Pkg.Operations /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:1958
[25] test
@ /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/Operations.jl:1902 [inlined]
[26] test(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}; coverage::Bool, test_fn::Nothing, julia_args::Cmd, test_args::Cmd, force_latest_compatible_version::Bool, allow_earlier_backwards_compatible_versions::Bool, allow_reresolve::Bool, kwargs::Base.Pairs{Symbol, Base.TTY, Tuple{Symbol}, NamedTuple{(:io,), Tuple{Base.TTY}}})
@ Pkg.API /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/API.jl:441
[27] test(pkgs::Vector{Pkg.Types.PackageSpec}; io::Base.TTY, kwargs::Base.Pairs{Symbol, Bool, Tuple{Symbol}, NamedTuple{(:force_latest_compatible_version,), Tuple{Bool}}})
@ Pkg.API /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/API.jl:156
[28] test(; name::Nothing, uuid::Nothing, version::Nothing, url::Nothing, rev::Nothing, path::Nothing, mode::Pkg.Types.PackageMode, subdir::Nothing, kwargs::Base.Pairs{Symbol, Bool, Tuple{Symbol}, NamedTuple{(:force_latest_compatible_version,), Tuple{Bool}}})
@ Pkg.API /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/Pkg/src/API.jl:171
[29] top-level scope
@ /private/tmp/Tester/bin/mwe.jl:4
in expression starting at /private/tmp/Tester/bin/mwe.jl:4
This came up for me when testing a CompatHelper pull request, and only on Julia v1.9: https://github.com/anowacki/Beamforming.jl/actions/runs/6746373999/job/18340164600?pr=3.