From 20d87db84f20b4fe0ae77f62c2450a3129c95c98 Mon Sep 17 00:00:00 2001
From: Vasileios Karakasis <vkarak@gmail.com>
Date: Thu, 21 May 2026 00:18:03 +0200
Subject: [PATCH] New option `--warn-as-error` for treating warnings as errors

Signed-off-by: Vasileios Karakasis <vkarak@gmail.com>
---
 docs/manpage.rst           | 21 +++++++++++++++++++++
 reframe/core/exceptions.py |  4 ++++
 reframe/core/logging.py    | 10 ++++++++--
 reframe/frontend/cli.py    |  7 ++++++-
 unittests/test_cli.py      | 11 +++++++++++
 5 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/docs/manpage.rst b/docs/manpage.rst
index b6859f6f7..cad711854 100644
--- a/docs/manpage.rst
+++ b/docs/manpage.rst
@@ -1254,6 +1254,14 @@ Miscellaneous options
 
    This option can also be set using the :envvar:`RFM_VERBOSE` environment variable or the :attr:`~config.general.verbose` general configuration parameter.
 
+.. option:: --warn-as-error
+
+   Treat warnings as errors.
+
+   This option can also be set using the :envvar:`RFM_WARN_AS_ERROR` environment variable.
+
+   .. versionadded:: 4.10
+
 
 .. _test_naming_scheme:
 
@@ -2633,6 +2641,19 @@ Whenever an environment variable is associated with a configuration option, its
       ================================== ==================
 
 
+.. envvar:: RFM_WARN_AS_ERROR
+
+   Treat warnings as errors.
+
+   .. table::
+      :align: left
+
+      ================================== ==================
+      Associated command line option     :option:`--warn-as-error`
+      Associated configuration parameter N/A
+      ================================== ==================
+
+
 .. _manpage-configuration:
 
 Configuration
diff --git a/reframe/core/exceptions.py b/reframe/core/exceptions.py
index 4a6853ca4..3d1043b6a 100644
--- a/reframe/core/exceptions.py
+++ b/reframe/core/exceptions.py
@@ -365,6 +365,10 @@ class ReferenceParseError(ReframeError):
     '''
 
 
+class WarningAsError(ReframeError):
+    '''Raised when a warning is treated as an error.'''
+
+
 def user_frame():
     '''Return the first user frame as a :py:class:`FrameInfo` object.
 
diff --git a/reframe/core/logging.py b/reframe/core/logging.py
index adff012f5..4e5cf97bd 100644
--- a/reframe/core/logging.py
+++ b/reframe/core/logging.py
@@ -22,7 +22,8 @@
 import reframe.utility.color as color
 import reframe.utility.jsonext as jsonext
 import reframe.utility.osext as osext
-from reframe.core.exceptions import ConfigError, LoggingError, what
+from reframe.core.exceptions import (ConfigError, LoggingError,
+                                     WarningAsError, what)
 from reframe.core.warnings import suppress_deprecations
 from reframe.utility import is_trivially_callable
 from reframe.utility.profile import TimeProfiler
@@ -903,6 +904,7 @@ def __init__(self, logger=None, check=None):
         )
         self.check = check
         self.colorize = False
+        self.warn_as_error = False
 
     def setLevel(self, level):
         if self.logger:
@@ -999,6 +1001,9 @@ def verbose(self, message, *args, **kwargs):
         self.log(VERBOSE, message, *args, **kwargs)
 
     def warning(self, message, *args, cache=False, **kwargs):
+        if self.warn_as_error:
+            raise WarningAsError(message)
+
         if cache:
             if message in _WARN_ONCE:
                 return
@@ -1082,7 +1087,7 @@ def __exit__(self, exc_type, exc_value, traceback):
         _context_logger = self._orig_logger
 
 
-def configure_logging(site_config):
+def configure_logging(site_config, warn_as_error=False):
     global _logger, _context_logger, _perf_logger
 
     if site_config is None:
@@ -1095,6 +1100,7 @@ def configure_logging(site_config):
     _logger = _create_logger(site_config, 'handlers$', 'handlers')
     _perf_logger = _create_logger(site_config, 'handlers_perflog')
     _context_logger = LoggerAdapter(_logger)
+    _context_logger.warn_as_error = warn_as_error
 
 
 def log_files():
diff --git a/reframe/frontend/cli.py b/reframe/frontend/cli.py
index 2da918a94..2b605a7cc 100644
--- a/reframe/frontend/cli.py
+++ b/reframe/frontend/cli.py
@@ -719,6 +719,11 @@ def main():
         '-q', '--quiet', action='count', default=0,
         help='Decrease verbosity level of output',
     )
+    misc_options.add_argument(
+        '--warn-as-error', action='store_true',
+        help='Treat warnings as errors',
+        envvar='RFM_WARN_AS_ERROR'
+    )
 
     # Options not associated with command-line arguments
     argparser.add_argument(
@@ -1076,7 +1081,7 @@ def restrict_logging():
                 options = argparser.parse_args(namespace=options.cmd_options)
                 options.update_config(site_config)
 
-        logging.configure_logging(site_config)
+        logging.configure_logging(site_config, options.warn_as_error)
     except (OSError, errors.ConfigError) as e:
         printer.error(f'failed to load configuration: {e}')
         printer.info(logfiles_message())
diff --git a/unittests/test_cli.py b/unittests/test_cli.py
index e0224a243..efee36fbc 100644
--- a/unittests/test_cli.py
+++ b/unittests/test_cli.py
@@ -1372,6 +1372,17 @@ def test_testlib_inherit_fixture_in_different_files(run_reframe):
     assert 'FAILED' not in stdout
 
 
+def test_warn_as_error(run_reframe):
+    returncode, stdout, stderr = run_reframe(
+        checkpath=['/unknown/path'],
+        more_options=['--warn-as-error']
+    )
+    assert 'Traceback' not in stdout
+    assert 'Traceback' not in stderr
+    assert returncode == 1
+    assert 'warning as error' in stdout
+
+
 @pytest.fixture(params=['csv', 'plain', 'pretty'])
 def table_format(request):
     return request.param