FIX: Disallow returning None in pipeline.utils.load_resultfile

nipype/pipeline/engine/nodes.py

@@ -195,7 +195,7 @@ def interface(self):
     def result(self):
         """Get result from result file (do not hold it in memory)"""
         return _load_resultfile(
-            op.join(self.output_dir(), 'result_%s.pklz' % self.name))[0]
+            op.join(self.output_dir(), 'result_%s.pklz' % self.name))
 
     @property
     def inputs(self):
@@ -518,7 +518,7 @@ def _get_inputs(self):
             logger.debug('input: %s', key)
             results_file = info[0]
             logger.debug('results file: %s', results_file)
-            outputs = _load_resultfile(results_file)[0].outputs
+            outputs = _load_resultfile(results_file).outputs
             if outputs is None:
                 raise RuntimeError("""\
 Error populating the input "%s" of node "%s": the results file of the source node \
@@ -565,34 +565,42 @@ def _run_interface(self, execute=True, updatehash=False):
 
     def _load_results(self):
         cwd = self.output_dir()
-        result, aggregate, attribute_error = _load_resultfile(
-            op.join(cwd, 'result_%s.pklz' % self.name))
+
+        try:
+            result = _load_resultfile(
+                op.join(cwd, 'result_%s.pklz' % self.name))
+        except (traits.TraitError, EOFError):
+            logger.debug(
+                'Error populating inputs/outputs, (re)aggregating results...')
+        except (AttributeError, ImportError) as err:
+            logger.debug('attribute error: %s probably using '
+                         'different trait pickled file', str(err))
+            old_inputs = loadpkl(op.join(cwd, '_inputs.pklz'))
+            self.inputs.trait_set(**old_inputs)
+        else:
+            return result
+
         # try aggregating first
-        if aggregate:
-            logger.debug('aggregating results')
-            if attribute_error:
-                old_inputs = loadpkl(op.join(cwd, '_inputs.pklz'))
-                self.inputs.trait_set(**old_inputs)
-            if not isinstance(self, MapNode):
-                self._copyfiles_to_wd(linksonly=True)
-                aggouts = self._interface.aggregate_outputs(
-                    needed_outputs=self.needed_outputs)
-                runtime = Bunch(
-                    cwd=cwd,
-                    returncode=0,
-                    environ=dict(os.environ),
-                    hostname=socket.gethostname())
-                result = InterfaceResult(
-                    interface=self._interface.__class__,
-                    runtime=runtime,
-                    inputs=self._interface.inputs.get_traitsfree(),
-                    outputs=aggouts)
-                _save_resultfile(
-                    result, cwd, self.name,
-                    rebase=str2bool(self.config['execution']['use_relative_paths']))
-            else:
-                logger.debug('aggregating mapnode results')
-                result = self._run_interface()
+        if not isinstance(self, MapNode):
+            self._copyfiles_to_wd(linksonly=True)
+            aggouts = self._interface.aggregate_outputs(
+                needed_outputs=self.needed_outputs)
+            runtime = Bunch(
+                cwd=cwd,
+                returncode=0,
+                environ=dict(os.environ),
+                hostname=socket.gethostname())
+            result = InterfaceResult(
+                interface=self._interface.__class__,
+                runtime=runtime,
+                inputs=self._interface.inputs.get_traitsfree(),
+                outputs=aggouts)
+            _save_resultfile(
+                result, cwd, self.name,
+                rebase=str2bool(self.config['execution']['use_relative_paths']))
+        else:
+            logger.debug('aggregating mapnode results')
+            result = self._run_interface()
         return result
 
     def _run_command(self, execute, copyfiles=True):

nipype/pipeline/engine/tests/test_utils.py

@@ -16,7 +16,8 @@
 from ....interfaces import base as nib
 from ....interfaces import utility as niu
 from .... import config
-from ..utils import clean_working_directory, write_workflow_prov
+from ..utils import (clean_working_directory, write_workflow_prov,
+                     load_resultfile)
 
 
 class InputSpec(nib.TraitedSpec):
@@ -283,3 +284,49 @@ def test_modify_paths_bug(tmpdir):
     assert outputs.out_dict_path == {out_str: out_path}
     assert outputs.out_dict_str == {out_str: out_str}
     assert outputs.out_list == [out_str] * 2
+
+
+@pytest.mark.xfail(sys.version_info < (3, 4),
+                   reason="rebase does not fully work with Python 2.7")
+@pytest.mark.parametrize("use_relative", [True, False])
+def test_save_load_resultfile(tmpdir, use_relative):
+    """Test minimally the save/load functions for result files."""
+    from shutil import copytree, rmtree
+    tmpdir.chdir()
+
+    old_use_relative = config.getboolean('execution', 'use_relative_paths')
+    config.set('execution', 'use_relative_paths', use_relative)
+
+    spc = pe.Node(StrPathConfuser(in_str='2'), name='spc')
+    spc.base_dir = tmpdir.mkdir('node').strpath
+
+    result = spc.run()
+
+    loaded_result = load_resultfile(
+        tmpdir.join('node').join('spc').join('result_spc.pklz').strpath)
+
+    assert result.runtime.dictcopy() == loaded_result.runtime.dictcopy()
+    assert result.inputs == loaded_result.inputs
+    assert result.outputs.get() == loaded_result.outputs.get()
+
+    # Test the mobility of the result file.
+    copytree(tmpdir.join('node').strpath, tmpdir.join('node2').strpath)
+    rmtree(tmpdir.join('node').strpath)
+
+    if use_relative:
+        loaded_result2 = load_resultfile(
+            tmpdir.join('node2').join('spc').join('result_spc.pklz').strpath)
+
+        assert result.runtime.dictcopy() == loaded_result2.runtime.dictcopy()
+        assert result.inputs == loaded_result2.inputs
+        assert loaded_result2.outputs.get() != result.outputs.get()
+        newpath = result.outputs.out_path.replace('/node/', '/node2/')
+        assert loaded_result2.outputs.out_path == newpath
+        assert loaded_result2.outputs.out_tuple[0] == newpath
+        assert loaded_result2.outputs.out_dict_path['2'] == newpath
+    else:
+        with pytest.raises(nib.TraitError):
+            load_resultfile(
+                tmpdir.join('node2').join('spc').join('result_spc.pklz').strpath)
+
+    config.set('execution', 'use_relative_paths', old_use_relative)

nipype/pipeline/engine/utils.py

@@ -38,11 +38,12 @@
     write_rst_header,
     write_rst_dict,
     write_rst_list,
+    FileNotFoundError,
 )
 from ...utils.misc import str2bool
 from ...utils.functions import create_function_from_source
 from ...interfaces.base.traits_extension import (
-    rebase_path_traits, resolve_path_traits, OutputMultiPath, isdefined, Undefined, traits)
+    rebase_path_traits, resolve_path_traits, OutputMultiPath, isdefined, Undefined)
 from ...interfaces.base.support import Bunch, InterfaceResult
 from ...interfaces.base import CommandLine
 from ...interfaces.utility import IdentityInterface
@@ -249,6 +250,10 @@ def save_resultfile(result, cwd, name, rebase=None):
         savepkl(resultsfile, result)
         return
 
+    if not rebase:
+        savepkl(resultsfile, result)
+        return
+
     backup_traits = {}
     try:
         with indirectory(cwd):
@@ -273,58 +278,44 @@ def load_resultfile(results_file, resolve=True):
     """
     Load InterfaceResult file from path.
 
-    Parameter
-    ---------
-    path : base_dir of node
-    name : name of node
+    Parameters
+    ----------
+    results_file : pathlike
+        Path to an existing pickle (``result_<interface name>.pklz``) created with
+        ``save_resultfile``.
+        Raises ``FileNotFoundError`` if ``results_file`` does not exist.
+    resolve : bool
+        Determines whether relative paths will be resolved to absolute (default is ``True``).
 
     Returns
     -------
-    result : InterfaceResult structure
-    aggregate : boolean indicating whether node should aggregate_outputs
-    attribute error : boolean indicating whether there was some mismatch in
-        versions of traits used to store result and hence node needs to
-        rerun
+    result : InterfaceResult
+        A Nipype object containing the runtime, inputs, outputs and other interface information
+        such as a traceback in the case of errors.
 
     """
     results_file = Path(results_file)
-    aggregate = True
-    result = None
-    attribute_error = False
-
     if not results_file.exists():
-        return result, aggregate, attribute_error
+        raise FileNotFoundError(results_file)
 
-    with indirectory(str(results_file.parent)):
+    result = loadpkl(results_file)
+    if resolve and result.outputs:
         try:
-            result = loadpkl(results_file)
-        except (traits.TraitError, EOFError):
-            logger.debug(
-                'some file does not exist. hence trait cannot be set')
-        except (AttributeError, ImportError) as err:
-            attribute_error = True
-            logger.debug('attribute error: %s probably using '
-                         'different trait pickled file', str(err))
-        else:
-            aggregate = False
-
-        if resolve and result.outputs:
-            try:
-                outputs = result.outputs.get()
-            except TypeError:  # This is a Bunch
-                return result, aggregate, attribute_error
-
-            logger.debug('Resolving paths in outputs loaded from results file.')
-            for trait_name, old in list(outputs.items()):
-                if isdefined(old):
-                    if result.outputs.trait(trait_name).is_trait_type(OutputMultiPath):
-                        old = result.outputs.trait(trait_name).handler.get_value(
-                            result.outputs, trait_name)
-                    value = resolve_path_traits(result.outputs.trait(trait_name), old,
-                                                results_file.parent)
-                    setattr(result.outputs, trait_name, value)
-
-    return result, aggregate, attribute_error
+            outputs = result.outputs.get()
+        except TypeError:  # This is a Bunch
+            logger.debug('Outputs object of loaded result %s is a Bunch.', results_file)
+            return result
+
+        logger.debug('Resolving paths in outputs loaded from results file.')
+        for trait_name, old in list(outputs.items()):
+            if isdefined(old):
+                if result.outputs.trait(trait_name).is_trait_type(OutputMultiPath):
+                    old = result.outputs.trait(trait_name).handler.get_value(
+                        result.outputs, trait_name)
+                value = resolve_path_traits(result.outputs.trait(trait_name), old,
+                                            results_file.parent)
+                setattr(result.outputs, trait_name, value)
+    return result
 
 
 def strip_temp(files, wd):

nipype/pipeline/plugins/tools.py

@@ -16,7 +16,7 @@
 from traceback import format_exception
 
 from ... import logging
-from ...utils.filemanip import savepkl, crash2txt, makedirs
+from ...utils.filemanip import savepkl, crash2txt, makedirs, FileNotFoundError
 
 logger = logging.getLogger('nipype.workflow')
 
@@ -26,17 +26,30 @@ def report_crash(node, traceback=None, hostname=None):
     """
     name = node._id
     host = None
-    if node.result and getattr(node.result, 'runtime'):
-        if isinstance(node.result.runtime, list):
-            host = node.result.runtime[0].hostname
-        else:
-            host = node.result.runtime.hostname
+    traceback = traceback or format_exception(*sys.exc_info())
+
+    try:
+        result = node.result
+    except FileNotFoundError:
+        traceback += """
+
+When creating this crashfile, the results file corresponding
+to the node could not be found.""".splitlines(keepends=True)
+    except Exception as exc:
+        traceback += """
+
+During the creation of this crashfile triggered by the above exception,
+another exception occurred:\n\n{}.""".format(exc).splitlines(keepends=True)
+    else:
+        if getattr(result, 'runtime', None):
+            if isinstance(result.runtime, list):
+                host = result.runtime[0].hostname
+            else:
+                host = result.runtime.hostname
 
     # Try everything to fill in the host
     host = host or hostname or gethostname()
     logger.error('Node %s failed to run on host %s.', name, host)
-    if not traceback:
-        traceback = format_exception(*sys.exc_info())
     timeofcrash = strftime('%Y%m%d-%H%M%S')
     try:
         login_name = getpass.getuser()
@@ -49,7 +62,7 @@ def report_crash(node, traceback=None, hostname=None):
     makedirs(crashdir, exist_ok=True)
     crashfile = os.path.join(crashdir, crashfile)
 
-    if node.config['execution']['crashfile_format'].lower() in ['text', 'txt']:
+    if node.config['execution']['crashfile_format'].lower() in ('text', 'txt', '.txt'):
         crashfile += '.txt'
     else:
         crashfile += '.pklz'

nipype/utils/filemanip.py

@@ -708,7 +708,7 @@ def loadpkl(infile):
 Attempted to open a results file generated by Nipype version %s, \
 with an incompatible Nipype version (%s)""", pkl_metadata['version'], version)
                             raise e
-                    fmlogger.error("""\
+                    fmlogger.warning("""\
 No metadata was found in the pkl file. Make sure you are currently using \
 the same Nipype version from the generated pkl.""")
                     raise e