cedws Terragrunt 1.0
This overview applies to target Terragrunt versions of at least 1.0.
Stability guarantee
Terragrunt 1.0 guarantees no breaking changes in minor 1.x releases; future breaking changes are reserved for a later major release. The maintained 1.0 Guarantees document defines boundary cases.
Execution and discovery
Breaking change: every run uses a .terragrunt-cache directory, even without a terraform.source. Hidden unit files needed in the cache belong in terraform.include_in_copy.
Breaking change: the embedded TFLint was removed. TFLint hooks require an installed external binary, while Terragrunt retains integration conveniences such as tflint init.
Breaking change: find and list discover hidden configurations, including .terragrunt-stack, by default. The deprecated --hidden is a no-op; --no-hidden opts out.
Breaking change: render --format=json no longer discovers dependants. Graph filters on find provide that traversal. A directory containing both terragrunt.hcl and terragrunt.stack.hcl is now rejected as ambiguous.
On Windows, path-returning HCL functions emit native separators. Configurations requiring slash-normalised keys can transform the returned string explicitly.
Reporting and delegation
The --report-file flag supports single-unit runs. Undefined flags that appear intended for OpenTofu or Terraform produce guidance to forward them after --.
Terragrunt 1.0 was continuously tested with OpenTofu 1.11.4 and Terraform 1.14.4; those are delegated-tool compatibility observations, not bundled versions.