Got type *generator.Package has no field or method AddFunction when run go build

[chengcheng-pei]

No idea whether I should put the issue here. But could someone help me with this problem?

$ git clone git@github.com:burdiyan/schemagen.git
Cloning into 'schemagen'...
remote: Enumerating objects: 777, done.
remote: Total 777 (delta 0), reused 0 (delta 0), pack-reused 777
Receiving objects: 100% (777/777), 1.28 MiB | 5.63 MiB/s, done.
Resolving deltas: 100% (243/243), done.
$ cd schemagen/
$ git branch
* master
$ go clean
$ go get
# gopkg.in/alanctgardner/gogen-avro.v5/types
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:98:3: p.AddFunction undefined (type *generator.Package has no field or method AddFunction)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:99:3: p.AddFunction undefined (type *generator.Package has no field or method AddFunction)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:100:3: p.AddFunction undefined (type *generator.Package has no field or method AddFunction)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:101:3: p.AddStruct undefined (type *generator.Package has no field or method AddStruct)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:102:3: p.AddImport undefined (type *generator.Package has no field or method AddImport)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:110:3: p.AddFunction undefined (type *generator.Package has no field or method AddFunction)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:111:3: p.AddFunction undefined (type *generator.Package has no field or method AddFunction)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/array.go:112:3: p.AddImport undefined (type *generator.Package has no field or method AddImport)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/bool.go:77:3: p.AddStruct undefined (type *generator.Package has no field or method AddStruct)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/bool.go:78:3: p.AddFunction undefined (type *generator.Package has no field or method AddFunction)
../gocode/src/gopkg.in/alanctgardner/gogen-avro.v5/types/bool.go:78:3: too many errors

I git cloned https://github.com/burdiyan/schemagen. I run git build and then got the above error. Could someone help with this? Thanks