Unable to create `range` with `°C` unit

I'm having issues creating a `range` defined with `°C` unit (and `K` for step unit). After trying different approaches, the only working solution was to directly create one using `StepRange` or `StepRangeLen` with explicit types. But then it still had an issue with printing.

Is there a better known approach for this? I may open up a PR for at least taking care of the printing issue for now.

1. `StepRange`
```
julia> (1:3)*u"°C"
ERROR: AffineError: an invalid operation was attempted with affine quantities: rem(2 K, 1 °C)
Stacktrace:
[1] _affineerror(::Function, ::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, ::Vararg{Any})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:98
[2] rem(x::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, y::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:115
[3] steprange_last
@ ./range.jl:346 [inlined]
[4] StepRange
@ ./range.jl:316 [inlined]
[5] StepRange
@ ./range.jl:369 [inlined]
[6] *(r::UnitRange{Int64}, y::Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/range.jl:141
[7] top-level scope
@ REPL[27]:1
```

2. `StepRangeLen`
```
julia> (1:1.0:3)*u"°C"
Error showing value of type StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64}:
ERROR: AffineError: an invalid operation was attempted with affine quantities: 1.0 °C*0
Stacktrace:
[1] *(x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, y::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:34
[2] *(y::Int64, x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:32
[3] unsafe_getindex
@ ./twiceprecision.jl:500 [inlined]
[4] first(r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Base ./range.jl:818
[5] show(io::IOContext{Base.TTY}, r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/display.jl:149
[6] show(io::IOContext{Base.TTY}, #unused#::MIME{Symbol("text/plain")}, r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Base ./show.jl:11
[7] (::REPL.var"#43#44"{REPL.REPLDisplay{REPL.LineEditREPL}, MIME{Symbol("text/plain")}, Base.RefValue{Any}})(io::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:267
[8] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:521
[9] display(d::REPL.REPLDisplay, mime::MIME{Symbol("text/plain")}, x::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:260
[10] display(d::REPL.REPLDisplay, x::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:272
[11] display(x::Any)
@ Base.Multimedia ./multimedia.jl:328
[12] #invokelatest#2
@ ./essentials.jl:729 [inlined]
[13] invokelatest
@ ./essentials.jl:726 [inlined]
[14] print_response(errio::IO, response::Any, show_value::Bool, have_color::Bool, specialdisplay::Union{Nothing, AbstractDisplay})
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:296
[15] (::REPL.var"#45#46"{REPL.LineEditREPL, Pair{Any, Bool}, Bool, Bool})(io::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:278
[16] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:521
[17] print_response(repl::REPL.AbstractREPL, response::Any, show_value::Bool, have_color::Bool)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:276
[18] (::REPL.var"#do_respond#66"{Bool, Bool, REPL.var"#77#87"{REPL.LineEditREPL, REPL.REPLHistoryProvider}, REPL.LineEditREPL, REPL.LineEdit.Prompt})(s::REPL.LineEdit.MIState, buf::Any, ok::Bool)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:857
[19] #invokelatest#2
@ ./essentials.jl:729 [inlined]
[20] invokelatest
@ ./essentials.jl:726 [inlined]
[21] run_interface(terminal::REPL.Terminals.TextTerminal, m::REPL.LineEdit.ModalInterface, s::REPL.LineEdit.MIState)
@ REPL.LineEdit /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/LineEdit.jl:2510
[22] run_frontend(repl::REPL.LineEditREPL, backend::REPL.REPLBackendRef)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:1248
[23] (::REPL.var"#49#54"{REPL.LineEditREPL, REPL.REPLBackendRef})()
@ REPL ./task.jl:484
```

In this case, an instance of `StepRangeLen` is actually created, but cannot be printed, collected, etc.

```
julia> r = (1:1.0:3)*u"°C";

julia> typeof(r)
StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64}

julia> r
Error showing value of type StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64}:
ERROR: AffineError: an invalid operation was attempted with affine quantities: 1.0 °C*0
Stacktrace:
[1] *(x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, y::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:34
[2] *(y::Int64, x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:32
[3] unsafe_getindex
@ ./twiceprecision.jl:500 [inlined]
[4] first(r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Base ./range.jl:818
[5] show(io::IOContext{Base.TTY}, r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/display.jl:149
[6] show(io::IOContext{Base.TTY}, #unused#::MIME{Symbol("text/plain")}, r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Base ./show.jl:11
[7] (::REPL.var"#43#44"{REPL.REPLDisplay{REPL.LineEditREPL}, MIME{Symbol("text/plain")}, Base.RefValue{Any}})(io::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:267
[8] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:521
[9] display(d::REPL.REPLDisplay, mime::MIME{Symbol("text/plain")}, x::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:260
[10] display(d::REPL.REPLDisplay, x::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:272
[11] display(x::Any)
@ Base.Multimedia ./multimedia.jl:328
[12] #invokelatest#2
@ ./essentials.jl:729 [inlined]
[13] invokelatest
@ ./essentials.jl:726 [inlined]
[14] print_response(errio::IO, response::Any, show_value::Bool, have_color::Bool, specialdisplay::Union{Nothing, AbstractDisplay})
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:296
[15] (::REPL.var"#45#46"{REPL.LineEditREPL, Pair{Any, Bool}, Bool, Bool})(io::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:278
[16] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:521
[17] print_response(repl::REPL.AbstractREPL, response::Any, show_value::Bool, have_color::Bool)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:276
[18] (::REPL.var"#do_respond#66"{Bool, Bool, REPL.var"#77#87"{REPL.LineEditREPL, REPL.REPLHistoryProvider}, REPL.LineEditREPL, REPL.LineEdit.Prompt})(s::REPL.LineEdit.MIState, buf::Any, ok::Bool)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:857
[19] #invokelatest#2
@ ./essentials.jl:729 [inlined]
[20] invokelatest
@ ./essentials.jl:726 [inlined]
[21] run_interface(terminal::REPL.Terminals.TextTerminal, m::REPL.LineEdit.ModalInterface, s::REPL.LineEdit.MIState)
@ REPL.LineEdit /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/LineEdit.jl:2510
[22] run_frontend(repl::REPL.LineEditREPL, backend::REPL.REPLBackendRef)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:1248
[23] (::REPL.var"#49#54"{REPL.LineEditREPL, REPL.REPLBackendRef})()
@ REPL ./task.jl:484

julia> collect(r)
ERROR: AffineError: an invalid operation was attempted with affine quantities: 1.0 °C*0
Stacktrace:
[1] *(x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, y::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:34
[2] *(y::Int64, x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:32
[3] unsafe_getindex
@ ./twiceprecision.jl:500 [inlined]
[4] iterate
@ ./range.jl:876 [inlined]
[5] iterate
@ ./range.jl:874 [inlined]
[6] vcat
@ ./range.jl:1354 [inlined]
[7] collect(r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Base ./range.jl:1362
[8] top-level scope
@ REPL[33]:1
```

3. `range()`
```
julia> range(1u"°C", step = 1u"K", length = 3)
ERROR: AffineError: an invalid operation was attempted with affine quantities: -5443//20 °C*2
Stacktrace:
[1] *(x::Quantity{Rational{Int64}, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, y::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:34
[2] range_start_step_length(a::Quantity{Rational{Int64}, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, step::Quantity{Rational{Int64}, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, len::Int64)
@ Base ./range.jl:204
[3] _range(a::Quantity{Rational{Int64}, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, step::Quantity{Rational{Int64}, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, #unused#::Nothing, len::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/range.jl:36
[4] _unitful_start_step_length(start::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, step::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, len::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/range.jl:54
[5] _range(a::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, step::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, #unused#::Nothing, len::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/range.jl:50
[6] range(start::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}; stop::Nothing, length::Int64, step::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}})
@ Base ./range.jl:138
[7] top-level scope
@ REPL[51]:1

julia> range(1.0u"°C", step = 1u"K", length = 3);

julia> range(1.0u"°C", step = 1u"K", length = 3)
Error showing value of type StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64}:
ERROR: AffineError: an invalid operation was attempted with affine quantities: -272.14999999999986 °C*0
Stacktrace:
[1] *(x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, y::Int64)
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:34
[2] *(y::Int64, x::Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:32
[3] unsafe_getindex
@ ./twiceprecision.jl:500 [inlined]
[4] first(r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Base ./range.jl:818
[5] show(io::IOContext{Base.TTY}, r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/display.jl:149
[6] show(io::IOContext{Base.TTY}, #unused#::MIME{Symbol("text/plain")}, r::StepRangeLen{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Base.TwicePrecision{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}, Int64})
@ Base ./show.jl:11
[7] (::REPL.var"#43#44"{REPL.REPLDisplay{REPL.LineEditREPL}, MIME{Symbol("text/plain")}, Base.RefValue{Any}})(io::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:267
[8] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:521
[9] display(d::REPL.REPLDisplay, mime::MIME{Symbol("text/plain")}, x::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:260
[10] display(d::REPL.REPLDisplay, x::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:272
[11] display(x::Any)
@ Base.Multimedia ./multimedia.jl:328
[12] #invokelatest#2
@ ./essentials.jl:729 [inlined]
[13] invokelatest
@ ./essentials.jl:726 [inlined]
[14] print_response(errio::IO, response::Any, show_value::Bool, have_color::Bool, specialdisplay::Union{Nothing, AbstractDisplay})
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:296
[15] (::REPL.var"#45#46"{REPL.LineEditREPL, Pair{Any, Bool}, Bool, Bool})(io::Any)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:278
[16] with_repl_linfo(f::Any, repl::REPL.LineEditREPL)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:521
[17] print_response(repl::REPL.AbstractREPL, response::Any, show_value::Bool, have_color::Bool)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:276
[18] (::REPL.var"#do_respond#66"{Bool, Bool, REPL.var"#77#87"{REPL.LineEditREPL, REPL.REPLHistoryProvider}, REPL.LineEditREPL, REPL.LineEdit.Prompt})(s::REPL.LineEdit.MIState, buf::Any, ok::Bool)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:857
[19] #invokelatest#2
@ ./essentials.jl:729 [inlined]
[20] invokelatest
@ ./essentials.jl:726 [inlined]
[21] run_interface(terminal::REPL.Terminals.TextTerminal, m::REPL.LineEdit.ModalInterface, s::REPL.LineEdit.MIState)
@ REPL.LineEdit /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/LineEdit.jl:2510
[22] run_frontend(repl::REPL.LineEditREPL, backend::REPL.REPLBackendRef)
@ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:1248
[23] (::REPL.var"#49#54"{REPL.LineEditREPL, REPL.REPLBackendRef})()
@ REPL ./task.jl:484
```

4. Direct Instantiation
```
julia> StepRangeLen(1u"°C", 1u"K", 3, 1)
(5483//20:1:5523//20) K
```

Above works in a way, but the final unit is fixed to K, not °C.

```
julia> U = typeof(1u"°C"); S = typeof(1u"K");

julia> r2 = StepRangeLen{U,U,S}(1u"°C", 1u"K", 3, 1)
(1//1:-5443//20:-5433//10) °C

julia> r2 |> collect
3-element Vector{Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}:
1 °C
2 °C
3 °C
```

This now works as intended, but printing is incorrect. The following example is more easy to see what happens when two units are mixed.

```
julia> U2 = typeof(1.0u"°C"); S = typeof(1u"K");

julia> r3 = StepRangeLen{U2,U2,S}(1.0u"°C", 1u"K", 3, 1)
(1.0:-272.15:-543.3) °C
```

It is rather supposed to be `(1.0:1.0:3.0) °C`. `collect()` still works fine though. It's more like a printing issue.

```
julia> r3 |> collect
3-element Vector{Quantity{Float64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}:
1.0 °C
2.0 °C
3.0 °C
```

The same goes for the case of `StepRange`.

```
julia> StepRange(1u"°C", 1u"°C", 3u"°C")
ERROR: AffineError: an invalid operation was attempted with affine quantities: rem(2 K, 1 °C)
Stacktrace:
[1] _affineerror(::Function, ::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, ::Vararg{Any})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:98
[2] rem(x::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, y::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:115
[3] steprange_last
@ ./range.jl:346 [inlined]
[4] StepRange
@ ./range.jl:316 [inlined]
[5] StepRange(start::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, step::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, stop::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Base ./range.jl:369
[6] top-level scope
@ REPL[46]:1

julia> StepRange(1u"°C", 1u"K", 3u"°C")
(1//1:-5443//20:3//1) °C

julia> StepRange(1u"°C", 1u"K", 3u"°C") |> collect
3-element Vector{Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}:
1 °C
2 °C
3 °C

julia> StepRange(1u"°C", 1.0u"K", 3u"°C")
(1.0:-272.15:273.15) °C

julia> StepRange(1u"°C", 1.0u"K", 3u"°C") |> collect
3-element Vector{Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}}:
1 °C
2 °C
3 °C
```

5. Alternative Syntax
```
julia> 1u"°C":10u"°C"
ERROR: AffineError: no multiplicative identity for affine quantity 1 °C.
Stacktrace:
[1] one(x::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:416
[2] (::Colon)(start::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, stop::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/range.jl:131
[3] top-level scope
@ REPL[5]:1

julia> 1u"°C":1u"°C":10u"°C"
ERROR: AffineError: an invalid operation was attempted with affine quantities: rem(9 K, 1 °C)
Stacktrace:
[1] _affineerror(::Function, ::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, ::Vararg{Any})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:98
[2] rem(x::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, nothing}}, y::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/quantities.jl:115
[3] steprange_last
@ ./range.jl:346 [inlined]
[4] StepRange
@ ./range.jl:316 [inlined]
[5] StepRange
@ ./range.jl:369 [inlined]
[6] _colon
@ ~/.julia/packages/Unitful/SUQzL/src/range.jl:108 [inlined]
[7] (::Colon)(start::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, step::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}}, stop::Quantity{Int64, 𝚯, Unitful.FreeUnits{(K,), 𝚯, Unitful.Affine{-5463//20}}})
@ Unitful ~/.julia/packages/Unitful/SUQzL/src/range.jl:106
[8] top-level scope
@ REPL[14]:1

julia> 1u"°C":1u"K":10u"°C"
(5483//20:5663//20) K

julia> 1u"°C":1.0u"K":10u"°C"
(274.15:1.0:283.15) K
```

~None of them works and this is more likely a limitation of Julia parser.~
Range notations with `:` only work when step values are explicitly provided in `K` unit, but then they always result into `K` even start/stop values are `°C`.

Reproduce the °C range cases and start by reading src/range.jl, src/quantities.jl, and src/display.jl, especially the paths shown in the stack traces. Determine the intended behavior for creating, printing, and collecting StepRange and StepRangeLen values with affine quantities, then verify that these operations no longer raise AffineError.

Written by the indexing model from the issue text.