Hello all, Not sure if the mailing list or trello would be appropriate for this. I had a problem using the gff_filter_by_attribute tool, both locally and on usegalaxy.org. Neither filtering for GTF or GFF were working. The error message was: Traceback (most recent call last): File "/home/galaxy/galaxy-dist/lib/galaxy/jobs/runners/__init__.py", line 158, in prepare_job job_wrapper.prepare() File "/home/galaxy/galaxy-dist/lib/galaxy/jobs/__init__.py", line 832, in prepare self.command_line, self.extra_filenames = tool_evaluator.build() File "/home/galaxy/galaxy-dist/lib/galaxy/tools/evaluation.py", line 408, in build self.__build_command_line( ) File "/home/galaxy/galaxy-dist/lib/galaxy/tools/evaluation.py", line 424, in __build_command_line command_line = fill_template( command, context=param_dict ) File "/home/galaxy/galaxy-dist/lib/galaxy/util/template.py", line 9, in fill_template return str( Template( source=template_text, searchList=[context] ) ) File "/home/galaxy/galaxy-dist/eggs/Cheetah-2.2.2-py2.7-linux-x86_64-ucs4.egg/Cheetah/Template.py", line 1004, in __str__ return getattr(self, mainMethName)() File "DynamicallyCompiledCheetahTemplate.py", line 92, in respond NotFound: cannot find 'attribute_types' while searching for 'input.metadata.attribute_types' I could fix it by importing safe_dumps from galaxy.util.json, which apparently was not imported. The next problem occurred because gff_filter_by_attribute expects GTF attribute name-value separators (" ") but allowed GFF input, which uses ("=") as separator. I added a logic to switch between seperators based on the file extension. Everything works smoothly now, the code changes are here: https://github.com/mvdbeek/galaxy Should I create a pull request? -- Marius van den Beek, PhD Drosophila Genetics and Epigenetics Institut de Biologie Paris Seine <http://www.ibps.upmc.fr/fr/Recherche/umr-biologie-developpement/genetique-et-epigenetique-de-la-drosophile> 9, Quai St Bernard, Boîte courrier 24 75252 Paris Cedex 05 Tel +33 01 44 27 34 01