Fix builds with Ninja 12 and remove a 5 year old workaround.

run_project_tests.py

@@ -45,7 +45,7 @@
 from mesonbuild.modules.python import PythonExternalProgram
 from run_tests import (
     get_fake_options, run_configure, get_meson_script, get_backend_commands,
-    get_backend_args_for_dir, Backend, ensure_backend_detects_changes,
+    get_backend_args_for_dir, Backend,
     guess_backend, handle_meson_skip_test,
 )
 
@@ -723,7 +723,6 @@ def build_step() -> None:
 
     # Touch the meson.build file to force a regenerate
     def force_regenerate() -> None:
-        ensure_backend_detects_changes(backend)
         os.utime(str(test.path / 'meson.build'))
 
     # just test building

run_tests.py

@@ -39,29 +39,27 @@
 if T.TYPE_CHECKING:
     from mesonbuild.coredata import SharedCMDOptions
 
-NINJA_1_9_OR_NEWER = False
+NINJA_1_12_OR_NEWER = False
 NINJA_CMD = None
 # If we're on CI, detecting ninja for every subprocess unit test that we run is slow
 # Optimize this by respecting $NINJA and skipping detection, then exporting it on
 # first run.
 try:
-    NINJA_1_9_OR_NEWER = bool(int(os.environ['NINJA_1_9_OR_NEWER']))
+    NINJA_1_12_OR_NEWER = bool(int(os.environ['NINJA_1_12_OR_NEWER']))
     NINJA_CMD = [os.environ['NINJA']]
 except (KeyError, ValueError):
-    # Look for 1.9 to see if https://github.com/ninja-build/ninja/issues/1219
-    # is fixed
-    NINJA_CMD = detect_ninja('1.9')
+    # Look for 1.12, which removes -w dupbuild=err
+    NINJA_CMD = detect_ninja('1.12')
     if NINJA_CMD is not None:
-        NINJA_1_9_OR_NEWER = True
+        NINJA_1_12_OR_NEWER = True
     else:
-        mlog.warning('Found ninja <1.9, tests will run slower', once=True)
         NINJA_CMD = detect_ninja()
 
 if NINJA_CMD is not None:
-    os.environ['NINJA_1_9_OR_NEWER'] = str(int(NINJA_1_9_OR_NEWER))
+    os.environ['NINJA_1_12_OR_NEWER'] = str(int(NINJA_1_12_OR_NEWER))
     os.environ['NINJA'] = NINJA_CMD[0]
 else:
-    raise RuntimeError('Could not find Ninja v1.7 or newer')
+    raise RuntimeError('Could not find Ninja.')
 
 # Emulate running meson with -X utf8 by making sure all open() calls have a
 # sane encoding. This should be a python default, but PEP 540 considered it not
@@ -271,7 +269,9 @@ def get_backend_commands(backend: Backend, debug: bool = False) -> \
         test_cmd = cmd + ['-target', 'RUN_TESTS']
     elif backend is Backend.ninja:
         global NINJA_CMD
-        cmd = NINJA_CMD + ['-w', 'dupbuild=err', '-d', 'explain']
+        cmd = NINJA_CMD + ['-d', 'explain']
+        if not NINJA_1_12_OR_NEWER:
+            cmd += ['-w', 'dupbuild=err']
         if debug:
             cmd += ['-v']
         clean_cmd = cmd + ['clean']
@@ -282,21 +282,6 @@ def get_backend_commands(backend: Backend, debug: bool = False) -> \
         raise AssertionError(f'Unknown backend: {backend!r}')
     return cmd, clean_cmd, test_cmd, install_cmd, uninstall_cmd
 
-def ensure_backend_detects_changes(backend: Backend) -> None:
-    global NINJA_1_9_OR_NEWER
-    if backend is not Backend.ninja:
-        return
-    need_workaround = False
-    # We're using ninja >= 1.9 which has QuLogic's patch for sub-1s resolution
-    # timestamps
-    if not NINJA_1_9_OR_NEWER:
-        mlog.warning('Don\'t have ninja >= 1.9, enabling timestamp resolution workaround', once=True)
-        need_workaround = True
-    # Increase the difference between build.ninja's timestamp and the timestamp
-    # of whatever you changed: https://github.com/ninja-build/ninja/issues/371
-    if need_workaround:
-        time.sleep(1)
-
 def run_mtest_inprocess(commandlist: T.List[str]) -> T.Tuple[int, str, str]:
     out = StringIO()
     with mock.patch.object(sys, 'stdout', out), mock.patch.object(sys, 'stderr', out):

unittests/baseplatformtests.py

@@ -31,7 +31,7 @@
 
 
 from run_tests import (
-    Backend, ensure_backend_detects_changes, get_backend_commands,
+    Backend, get_backend_commands,
     get_builddir_target_args, get_meson_script, run_configure_inprocess,
     run_mtest_inprocess, handle_meson_skip_test,
 )
@@ -294,8 +294,6 @@ def setconf(self, arg: T.Sequence[str], will_build: bool = True) -> None:
             arg = [arg]
         else:
             arg = list(arg)
-        if will_build:
-            ensure_backend_detects_changes(self.backend)
         self._run(self.mconf_command + arg + [self.builddir])
 
     def getconf(self, optname: str):
@@ -309,7 +307,6 @@ def wipe(self):
         windows_proof_rmtree(self.builddir)
 
     def utime(self, f):
-        ensure_backend_detects_changes(self.backend)
         os.utime(f)
 
     def get_compdb(self):