Panic : Elem of invalid type string

[muir]

     panic: reflect: Elem of invalid type string
     statesvc │ reflect.(*rtype).Elem(0x3f684e0?)
     statesvc │         /nix/store/m3mi5km1zdmaqdb33byirlixigzh3f4l-go-1.20.7/share/go/src/reflect/type.go:979 +0x134
     statesvc │ github.com/muir/nfigure.(*FlagHandler).Fill(0xc0001b92c0, {0x50887e0?, 0x3cee480}, {0x3cee480?, 0xc000604ed0?, 0xc001379800?}, {{0x4338cca, 0x4}, {0x4338cd0, 0x16}}, ...)
     statesvc │         go/pkg/mod/github.com/muir/[email protected]/flags_parse.go:318 +0x54c
     statesvc │ github.com/muir/nfigure.fillData.fillField({0xc00132ebd0, {0x4338c97, 0x13}, {{0xc0001f5f40, 0x2, 0x5}, 0xc001379800}, {{0x0, 0x0}, 0xc00137ad40, ...}, ...}, ...)
     statesvc │         go/pkg/mod/github.com/muir/[email protected]/fill.go:301 +0x23c
     statesvc │ github.com/muir/nfigure.fillData.recurseFillField({0xc00132ebd0, {0x4338c97, 0x13}, {{0xc0001f5f40, 0x2, 0x5}, 0xc001379800}, {{0x0, 0x0}, 0xc00137ad40, ...}, ...}, ...)
     statesvc │         go/pkg/mod/github.com/muir/[email protected]/fill.go:284 +0x185
     statesvc │ github.com/muir/nfigure.fillData.fillStruct({0xc00132ebd0, {0x0, 0x0}, {{0x0, 0x0, 0x0}, 0x0}, {{0x0, 0x0}, 0x0, ...}, ...}, ...)
     statesvc │         go/pkg/mod/github.com/muir/[email protected]/fill.go:241 +0x507
     statesvc │ github.com/muir/nfigure.(*Request).fill(0xc00132ebd0)
     statesvc │         go/pkg/mod/github.com/muir/[email protected]/fill.go:203 +0x451
     statesvc │ github.com/muir/nfigure.(*Registry).Configure(0xc00132eb60)
     statesvc │         go/pkg/mod/github.com/muir/[email protected]/registry.go:219 +0x1c6

Caused by providing the same command line flag twice when only a single string is expected.