fix(hooks): check terragrunt syntax version against tool_path, not $PATH

common::terragrunt_version_ge_0.78 ran bare `terragrunt --version`,
picking the CLI syntax (pre/post-0.78) based on whatever's on $PATH -
unrelated to the resolved/pinned binary that --tool-version actually
executes. A pinned version on the other side of the 0.78 boundary from
$PATH (or nothing on $PATH at all) picks the wrong subcommand syntax
and the hook fails.

Give the function a required tool_path argument and resolve it early
in each of the 4 terragrunt_*.sh hooks before the version-gate check,
mirroring terraform_tflint.sh's existing early-resolution precedent.

Assisted-by: Sisyphus:claude-sonnet-5 opencode

Author: MaxymVlasov

hooks/_common.sh

@@ -880,22 +880,27 @@ function common::export_provided_env_vars {
 }
 
 #######################################################################
-# Check if the installed Terragrunt version is >=0.78.0 or not
+# Check if the given Terragrunt binary's version is >=0.78.0 or not
 #
 # This function helps to determine which terragrunt subcomand to use
 # based on Terragrunt version
 #
+# Arguments:
+#   tool_path (string) resolved path to the terragrunt binary to check
+#     (the actually resolved/pinned binary, NOT whatever's on $PATH -
+#     those can differ once --tool-version is in play)
 # Returns:
 #   - 0 if version >= 0.78.0
 #   - 1 if version < 0.78.0
 #    Defaults to 0 if version cannot be determined
 #######################################################################
 # TODO: Drop after May 2027. Two years to upgrade is more than enough.
 function common::terragrunt_version_ge_0.78 {
+  local -r tool_path="$1"
   local terragrunt_version
 
   # Extract version number (e.g., "terragrunt version v0.80.4" -> "0.80")
-  terragrunt_version=$(terragrunt --version 2> /dev/null | grep -oE '[0-9]+\.[0-9]+')
+  terragrunt_version=$("$tool_path" --version 2> /dev/null | grep -oE '[0-9]+\.[0-9]+')
   # If we can't parse version, default to newer command
   [[ ! $terragrunt_version ]] && return 0
 

hooks/terragrunt_fmt.sh

@@ -14,14 +14,21 @@ function main {
   common::parse_and_export_env_vars
   # JFYI: `terragrunt hcl format` color already suppressed via PRE_COMMIT_COLOR=never
 
-  if common::terragrunt_version_ge_0.78; then
+  local -r tool_name="terragrunt"
+  # Needed early to pick the correct CLI syntax below against the actually
+  # resolved/pinned terragrunt binary, not whatever's on $PATH.
+  # common::per_dir_hook resolves it again for the per-dir runs.
+  local -r tool_version=$(common::get_hook_config_value "--tool-version")
+  local tool_path
+  tool_path=$(common::resolve_tool_path "$tool_name" "$tool_version") || exit $?
+  readonly tool_path
+
+  if common::terragrunt_version_ge_0.78 "$tool_path"; then
     local -ra SUBCOMMAND=(hcl format)
   else
     local -ra SUBCOMMAND=(hclfmt)
   fi
 
-  local -r tool_name="terragrunt"
-
   # shellcheck disable=SC2153 # False positive
   common::per_dir_hook "$HOOK_ID" "$tool_name" "${#ARGS[@]}" "${ARGS[@]}" "${FILES[@]}"
 }

hooks/terragrunt_providers_lock.sh

@@ -14,16 +14,23 @@ function main {
   common::parse_and_export_env_vars
   # JFYI: terragrunt providers lock color already suppressed via PRE_COMMIT_COLOR=never
 
-  if common::terragrunt_version_ge_0.78; then
+  local -r tool_name="terragrunt"
+  # Needed early to pick the correct CLI syntax below against the actually
+  # resolved/pinned terragrunt binary, not whatever's on $PATH.
+  # common::per_dir_hook resolves it again for the per-dir runs.
+  local -r tool_version=$(common::get_hook_config_value "--tool-version")
+  local tool_path
+  tool_path=$(common::resolve_tool_path "$tool_name" "$tool_version") || exit $?
+  readonly tool_path
+
+  if common::terragrunt_version_ge_0.78 "$tool_path"; then
     local -ra SUBCOMMAND=(run -- providers lock)
     local -ra RUN_ALL_SUBCOMMAND=(run --all -- providers lock)
   else
     local -ra SUBCOMMAND=(providers lock)
     local -ra RUN_ALL_SUBCOMMAND=(run-all providers lock)
   fi
 
-  local -r tool_name="terragrunt"
-
   # shellcheck disable=SC2153 # False positive
   common::per_dir_hook "$HOOK_ID" "$tool_name" "${#ARGS[@]}" "${ARGS[@]}" "${FILES[@]}"
 }

hooks/terragrunt_validate.sh

@@ -14,16 +14,23 @@ function main {
   common::parse_and_export_env_vars
   # JFYI: terragrunt validate color already suppressed via PRE_COMMIT_COLOR=never
 
-  if common::terragrunt_version_ge_0.78; then
+  local -r tool_name="terragrunt"
+  # Needed early to pick the correct CLI syntax below against the actually
+  # resolved/pinned terragrunt binary, not whatever's on $PATH.
+  # common::per_dir_hook resolves it again for the per-dir runs.
+  local -r tool_version=$(common::get_hook_config_value "--tool-version")
+  local tool_path
+  tool_path=$(common::resolve_tool_path "$tool_name" "$tool_version") || exit $?
+  readonly tool_path
+
+  if common::terragrunt_version_ge_0.78 "$tool_path"; then
     local -ra SUBCOMMAND=(run -- validate)
     local -ra RUN_ALL_SUBCOMMAND=(run --all -- validate)
   else
     local -ra SUBCOMMAND=(validate)
     local -ra RUN_ALL_SUBCOMMAND=(run-all validate)
   fi
 
-  local -r tool_name="terragrunt"
-
   # shellcheck disable=SC2153 # False positive
   common::per_dir_hook "$HOOK_ID" "$tool_name" "${#ARGS[@]}" "${ARGS[@]}" "${FILES[@]}"
 }

hooks/terragrunt_validate_inputs.sh

@@ -14,16 +14,23 @@ function main {
   common::parse_and_export_env_vars
   # JFYI: terragrunt validate color already suppressed via PRE_COMMIT_COLOR=never
 
-  if common::terragrunt_version_ge_0.78; then
+  local -r tool_name="terragrunt"
+  # Needed early to pick the correct CLI syntax below against the actually
+  # resolved/pinned terragrunt binary, not whatever's on $PATH.
+  # common::per_dir_hook resolves it again for the per-dir runs.
+  local -r tool_version=$(common::get_hook_config_value "--tool-version")
+  local tool_path
+  tool_path=$(common::resolve_tool_path "$tool_name" "$tool_version") || exit $?
+  readonly tool_path
+
+  if common::terragrunt_version_ge_0.78 "$tool_path"; then
     local -ra SUBCOMMAND=(hcl validate --inputs)
     local -ra RUN_ALL_SUBCOMMAND=(run --all hcl validate --inputs)
   else
     local -ra SUBCOMMAND=(validate-inputs)
     local -ra RUN_ALL_SUBCOMMAND=(run-all validate-inputs)
   fi
 
-  local -r tool_name="terragrunt"
-
   # shellcheck disable=SC2153 # False positive
   common::per_dir_hook "$HOOK_ID" "$tool_name" "${#ARGS[@]}" "${ARGS[@]}" "${FILES[@]}"
 }