if Viper is not set, go get fails

[georgettica]

go get .
# XXX/cmd
cmd/root.go:33:3: undefined: os

cobra/cobra/tpl/main.go

Line 72 in 1beb476

os.Exit(1)

[georgettica]

the testing steps are:

pushd $(mktemp -d)
git clone https://github.com/spf13/cobra.git
cd cobra
make cobra_generator
cd ../
mkdir example
cd example
go mod init example.com
../cobra/bin/cobra_linux_amd64 init
go build . # this works
../cobra/bin/cobra_linux_amd64 add foo
go build .
popd

[georgettica]

Thanks for the effort and quick fix 😊