unable to generate test cases (panic: invalid memory address (StdSizes nil) when running on go file)

[mdimado]

ran this:

~/go/bin/nxt_unit \
  -file_path=/home/user/project/message.go \
  -directory_path=/home/user/project \
  -receiver_name=Message \
  -function_name=Decode \
  -receiver_is_start \
  -usage=plugin

crashes with:

panic: runtime error: invalid memory address or nil pointer dereference
go/types.(*StdSizes).Sizeof(0x0, ...)

pretty sure it's because StdSizes is nil