Clarify message about an outdated lock file

As discussed in python-poetry#8737 (comment)

src/poetry/console/commands/check.py

@@ -147,8 +147,8 @@ def handle(self) -> int:
             check_result["errors"] += ["poetry.lock was not found."]
         if self.poetry.locker.is_locked() and not self.poetry.locker.is_fresh():
             check_result["errors"] += [
-                "poetry.lock is not consistent with pyproject.toml. Run `poetry"
-                " lock [--no-update]` to fix it."
+                "pyproject.toml changed significantly since poetry.lock was last generated. "
+                "Run `poetry lock [--no-update]` to fix the lock file."
             ]
 
         if not check_result["errors"] and not check_result["warnings"]:

src/poetry/console/commands/lock.py

@@ -44,8 +44,8 @@ def handle(self) -> int:
                 return 0
             self.line_error(
                 "<error>"
-                "Error: poetry.lock is not consistent with pyproject.toml. "
-                "Run `poetry lock [--no-update]` to fix it."
+                "Error: pyproject.toml changed significantly since poetry.lock was last generated. "
+                "Run `poetry lock [--no-update]` to fix the lock file."
                 "</error>"
             )
             return 1

src/poetry/installation/installer.py

@@ -246,8 +246,8 @@ def _do_install(self) -> int:
 
             if not self._locker.is_fresh():
                 raise ValueError(
-                    "poetry.lock is not consistent with pyproject.toml. "
-                    "Run `poetry lock [--no-update]` to fix it."
+                    "pyproject.toml changed significantly since poetry.lock was last generated. "
+                    "Run `poetry lock [--no-update]` to fix the lock file."
                 )
 
             locker_extras = {

tests/console/commands/test_check.py

@@ -171,8 +171,8 @@ def test_check_lock_outdated(
     tester = command_tester_factory("check", poetry=poetry_with_outdated_lockfile)
     status_code = tester.execute(options)
     expected = (
-        "Error: poetry.lock is not consistent with pyproject.toml. "
-        "Run `poetry lock [--no-update]` to fix it.\n"
+        "Error: pyproject.toml changed significantly since poetry.lock was last generated. "
+        "Run `poetry lock [--no-update]` to fix the lock file.\n"
     )
 
     assert tester.io.fetch_error() == expected

tests/console/commands/test_lock.py

@@ -106,8 +106,8 @@ def test_lock_check_outdated_legacy(
     status_code = tester.execute("--check")
     expected = (
         "poetry lock --check is deprecated, use `poetry check --lock` instead.\n"
-        "Error: poetry.lock is not consistent with pyproject.toml. "
-        "Run `poetry lock [--no-update]` to fix it.\n"
+        "Error: pyproject.toml changed significantly since poetry.lock was last generated. "
+        "Run `poetry lock [--no-update]` to fix the lock file.\n"
     )
 
     assert tester.io.fetch_error() == expected

tests/installation/test_installer.py

@@ -220,8 +220,8 @@ def test_not_fresh_lock(installer: Installer, locker: Locker) -> None:
     with pytest.raises(
         ValueError,
         match=re.escape(
-            "poetry.lock is not consistent with pyproject.toml. "
-            "Run `poetry lock [--no-update]` to fix it."
+            "pyproject.toml changed significantly since poetry.lock was last generated. "
+            "Run `poetry lock [--no-update]` to fix the lock file."
         ),
     ):
         installer.run()