Tests for terrgrunt plan WITHOUT --terragrunt-source passing

Works

git clone https://github.com/dsantanu/tg-sample-module.git
mkdir services && cd services
git clone https://github.com/dsantanu/tf-sample-moda.git
git clone https://github.com/dsantanu/tf-sample-modb.git
cd ../tg-sample-module/znp/moda/exc/
terragrunt plan --terragrunt-source ../../../../services//tf-sample-moda
cd ../../modb/exc/
terragrunt plan --terragrunt-source ../../../../services//tf-sample-modb

SHOULD Work but Does NOT

git clone https://github.com/dsantanu/tg-sample-module.git
cd tg-sample-module/znp/moda/exc/
terragrunt plan --terragrunt-log-level debug

Expected Result

Terragrunt should be able to do a successful plan/apply without locally cloning any TF modules at all. It should download the associated TF modules directly from the upstream in the temporary location, where it should be running terrafrom plan form.

References: gruntwork-io/knowledge-base#690