Use Hugo to render content from in-memory Go-Git’s billy.Filesystem in bare Git repo

&viper.Viper{keyDelim:".", configPaths:[]string(nil), fs:(*afero.OsFs)(0x222b3e8), remoteProviders:[]*viper.defaultRemoteProvider(nil), configName:"config", configFile:"", configType:"", configPermissions:0x1a4, envPrefix:"", automaticEnvApplied:false, envKeyReplacer:viper.StringReplacer(nil), allowEmptyEnv:false, config:map[string]interface {}{"baseurl":"http://example.org/", "languagecode":"en-us", "theme":"kiss", "title":"My New Hugo Site"}, override:map[string]interface {}{"languagessorted":langs.Languages{(*langs.Language)(0xc00054a1b0)}, "workingdir":"/tmp/barfoo"}, defaults:map[string]interface {}{}, kvstore:map[string]interface {}{}, pflags:map[string]viper.FlagValue{}, env:map[string]string{}, aliases:map[string]string{}, typeByDefValue:false, properties:(*properties.Properties)(nil), onConfigChange:(func(fsnotify.Event))(nil)}

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x78 pc=0x76052f]
goroutine 1 [running]:
github.com/spf13/afero.(*BasePathFs).LstatIfPossible(0xc00024f720, 0xc0005ee3a0, 0x7, 0x7f06fc5cc4d8, 0xc00024f720, 0x147ab01, 0x7f06fc64dba0, 0x8)
    /home/m/go/pkg/mod/github.com/spf13/afero@v1.5.1/basepath.go:183 +0x1cf
github.com/gohugoio/hugo/hugofs.lstatIfPossible(0x1a17140, 0xc00024f720, 0x0, 0x0, 0x8, 0x203000, 0x8, 0x203000, 0x7f0724434a68)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugofs/walk.go:143 +0x74
github.com/gohugoio/hugo/hugofs.(*FilterFs).LstatIfPossible(0xc00024f900, 0x0, 0x0, 0x10, 0x1355c40, 0xc00060d040, 0x0, 0x7f06fc64dba0)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugofs/filter_fs.go:145 +0x66
github.com/gohugoio/hugo/hugofs.(*FilterFs).Stat(0xc00024f900, 0x0, 0x0, 0x10, 0xc000000180, 0xe5dbc6, 0xc0006ff4c8)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugofs/filter_fs.go:205 +0x3f
github.com/gohugoio/hugo/hugolib.(*pagesCollector).collectDir(0xc00010faa0, 0x0, 0x0, 0x1a0bb00, 0x0, 0x222cd00, 0x7f06fc64dba0)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/pages_capture.go:328 +0x66github.com/gohugoio/hugo/hugolib.(*pagesCollector).Collect(0xc00010faa0, 0x0, 0x0)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/pages_capture.go:172 +0x639
github.com/gohugoio/hugo/hugolib.(*Site).readAndProcessContent(0xc000502fc0, 0x0, 0x0, 0x0, 0x12c5520, 0x1)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/site.go:1370 +0x185
github.com/gohugoio/hugo/hugolib.(*Site).process(0xc000502fc0, 0x0, 0x0, 0x0, 0x1, 0xc00060cd20, 0x0, 0x0, 0x0, 0x1, ...)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/site.go:1194 +0x65
github.com/gohugoio/hugo/hugolib.(*HugoSites).process(0xc0005400c0, 0xc000389400, 0xc0006ffb38, 0x0, 0x0, 0x0, 0x222b3e8, 0x11cf701)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/hugo_sites_build.go:245 +0x129
github.com/gohugoio/hugo/hugolib.(*HugoSites).Build.func3.2()
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/hugo_sites_build.go:118 +0x65
runtime/trace.WithRegion(0x1a0bc00, 0xc0005fc780, 0x148794a, 0x7, 0xc0006ffb60)
    /home/m/sdk/go1.16/src/runtime/trace/annotation.go:141 +0xf8
github.com/gohugoio/hugo/hugolib.(*HugoSites).Build.func3(0x222b3e8, 0x1)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/hugo_sites_build.go:120 +0x165
github.com/gohugoio/hugo/hugolib.(*HugoSites).Build.func4()
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/hugo_sites_build.go:137 +0x2fruntime/trace.WithRegion(0x1a0bc00, 0xc0005fc780, 0x14878e1, 0x7, 0xc0006ffd20)
    /home/m/sdk/go1.16/src/runtime/trace/annotation.go:141 +0xf8
github.com/gohugoio/hugo/hugolib.(*HugoSites).Build(0xc0005400c0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
    /home/m/go/pkg/mod/github.com/gohugoio/hugo@v0.81.0/hugolib/hugo_sites_build.go:139 +0xa57
main.main()
    /home/m/devel/mygodev/hugo_fs/main.go:41 +0x4ba