diff --git a/craft_parts/infos.py b/craft_parts/infos.py
index aba73359a..ef2523bd1 100644
--- a/craft_parts/infos.py
+++ b/craft_parts/infos.py
@@ -173,6 +173,11 @@ def project_name(self) -> Optional[str]:
         """Return the name of the project using craft-parts."""
         return self._project_name
 
+    @property
+    def project_vars_part_name(self) -> Optional[str]:
+        """Return the name of the part that can set project vars."""
+        return self._project_vars_part_name
+
     @property
     def project_options(self) -> Dict[str, Any]:
         """Obtain a project-wide options dictionary."""
diff --git a/craft_parts/sequencer.py b/craft_parts/sequencer.py
index ab6c75d81..66a396d9c 100644
--- a/craft_parts/sequencer.py
+++ b/craft_parts/sequencer.py
@@ -200,9 +200,16 @@ def _add_step_actions(
             current_step,
             action_type=ActionType.SKIP,
             reason="already ran",
-            project_vars=self._sm.project_vars(part, current_step),
+            project_vars=self._get_project_vars(part, current_step),
         )
 
+    def _get_project_vars(
+        self, part: Part, step: Step
+    ) -> Optional[Dict[str, ProjectVar]]:
+        if part.name == self._project_info.project_vars_part_name:
+            return self._sm.project_vars(part, step)
+        return None
+
     def _process_dependencies(self, part: Part, step: Step) -> None:
         prerequisite_step = steps.dependency_prerequisite_step(step)
         if not prerequisite_step:
diff --git a/tests/integration/lifecycle/test_craftctl.py b/tests/integration/lifecycle/test_craftctl.py
index 58f517b29..7649de5f5 100644
--- a/tests/integration/lifecycle/test_craftctl.py
+++ b/tests/integration/lifecycle/test_craftctl.py
@@ -23,7 +23,7 @@
 import yaml
 
 import craft_parts
-from craft_parts import Action, Step, errors
+from craft_parts import Action, ActionType, Step, errors
 from tests import TESTS_DIR
 
 
@@ -356,6 +356,117 @@ def test_craftctl_set_error(new_dir, capfd, mocker):
     assert "'myvar' not in project variables" in captured.err
 
 
+def test_craftctl_set_only_once(new_dir, capfd, mocker):  # see LP #1831135
+    parts_yaml = textwrap.dedent(
+        """\
+        parts:
+          part1:
+            plugin: nil
+            override-pull: |
+              craftctl default
+              craftctl set version=xx
+
+          part2:
+            plugin: nil
+            after: [part1]
+        """
+    )
+    parts = yaml.safe_load(parts_yaml)
+
+    lf = craft_parts.LifecycleManager(
+        parts,
+        application_name="test_set",
+        cache_dir=new_dir,
+        project_vars_part_name="part1",
+        project_vars={"version": ""},
+    )
+
+    assert lf.project_info.get_project_var("version", raw_read=True) == ""
+
+    actions = lf.plan(Step.BUILD)
+    with lf.action_executor() as ctx:
+        ctx.execute(actions)
+
+    assert lf.project_info.get_project_var("version") == "xx"
+
+    # change something in part1 to make it dirty
+    parts["parts"]["part1"]["override-pull"] += "\necho foo"
+
+    # now build only part2 so that pull order will be reversed
+    lf = craft_parts.LifecycleManager(
+        parts,
+        application_name="test_set",
+        cache_dir=new_dir,
+        project_vars_part_name="part1",
+        project_vars={"version": ""},
+    )
+
+    assert lf.project_info.get_project_var("version", raw_read=True) == ""
+
+    # execution of actions must succeed
+    actions = lf.plan(Step.BUILD, part_names=["part2"])
+    with lf.action_executor() as ctx:
+        ctx.execute(actions)
+
+    assert lf.project_info.get_project_var("version") == "xx"
+
+
+def test_craftctl_update_project_vars(new_dir, capfd, mocker):
+    parts_yaml = textwrap.dedent(
+        """\
+        parts:
+          part1:
+            plugin: nil
+            override-pull: |
+              craftctl default
+              craftctl set version=xx
+
+          part2:
+            plugin: nil
+            after: [part1]
+        """
+    )
+    parts = yaml.safe_load(parts_yaml)
+
+    lf = craft_parts.LifecycleManager(
+        parts,
+        application_name="test_set",
+        cache_dir=new_dir,
+        project_vars_part_name="part1",
+        project_vars={"version": ""},
+    )
+
+    assert lf.project_info.get_project_var("version", raw_read=True) == ""
+
+    actions = lf.plan(Step.BUILD)
+    with lf.action_executor() as ctx:
+        ctx.execute(actions)
+
+    assert lf.project_info.get_project_var("version") == "xx"
+
+    # re-execute the lifecycle with no changes
+    lf = craft_parts.LifecycleManager(
+        parts,
+        application_name="test_set",
+        cache_dir=new_dir,
+        project_vars_part_name="part1",
+        project_vars={"version": ""},
+    )
+
+    assert lf.project_info.get_project_var("version", raw_read=True) == ""
+
+    actions = lf.plan(Step.BUILD)
+
+    # all actions should be skipped
+    for action in actions:
+        assert action.action_type == ActionType.SKIP
+
+    with lf.action_executor() as ctx:
+        ctx.execute(actions)
+
+    assert lf.project_info.get_project_var("version") == "xx"
+
+
 def test_craftctl_get_error(new_dir, capfd, mocker):
     parts_yaml = textwrap.dedent(
         """\
diff --git a/tests/unit/test_infos.py b/tests/unit/test_infos.py
index c48697b9d..59246f247 100644
--- a/tests/unit/test_infos.py
+++ b/tests/unit/test_infos.py
@@ -69,6 +69,7 @@ def test_project_info(mocker, new_dir, tc_arch, tc_target_arch, tc_triplet, tc_c
         "project_vars_part_name": "adopt",
         "project_vars": {"a": ProjectVar(value="b")},
     }
+    assert x.project_vars_part_name == "adopt"
     assert x.global_environment == {}
 
     assert x.parts_dir == new_dir / "parts"