diff --git a/pubs/commands/doc_cmd.py b/pubs/commands/doc_cmd.py
index d1a44df..2bb6f9c 100644
--- a/pubs/commands/doc_cmd.py
+++ b/pubs/commands/doc_cmd.py
@@ -71,7 +71,7 @@ def command(conf, args):
     # ui.exit()
 
     if args.action == 'add':
-        citekey = resolve_citekey(rp, args.citekey[0], ui=ui, exit_on_fail=True)
+        citekey = resolve_citekey(rp, conf, args.citekey[0], ui=ui, exit_on_fail=True)
         paper = rp.pull_paper(citekey)
 
         if paper.docpath is not None and not args.force:
@@ -98,7 +98,7 @@ def command(conf, args):
 
     elif args.action == 'remove':
 
-        for key in resolve_citekey_list(rp, args.citekeys, ui=ui, exit_on_fail=True):
+        for key in resolve_citekey_list(rp, conf, args.citekeys, ui=ui, exit_on_fail=True):
             paper = rp.pull_paper(key)
 
             # if there is no document (and the user cares) -> inform + continue
@@ -126,7 +126,7 @@ def command(conf, args):
                 color.dye_err(args.path[0], 'filepath')))
             ui.exit(1)
 
-        for key in resolve_citekey_list(rp, args.citekeys, ui=ui, exit_on_fail=True):
+        for key in resolve_citekey_list(rp, conf, args.citekeys, ui=ui, exit_on_fail=True):
             try:
                 paper = rp.pull_paper(key)
                 doc = paper.docpath
@@ -143,7 +143,7 @@ def command(conf, args):
 
     elif args.action == 'open':
         with_command = args.cmd
-        citekey = resolve_citekey(rp, args.citekey[0], ui=ui, exit_on_fail=True)
+        citekey = resolve_citekey(rp, conf, args.citekey[0], ui=ui, exit_on_fail=True)
         paper = rp.pull_paper(citekey)
 
         if paper.docpath is None:
diff --git a/pubs/commands/edit_cmd.py b/pubs/commands/edit_cmd.py
index d4ad366..5ea7679 100644
--- a/pubs/commands/edit_cmd.py
+++ b/pubs/commands/edit_cmd.py
@@ -30,7 +30,7 @@ def command(conf, args):
     meta = args.meta
 
     rp = repo.Repository(conf)
-    citekey = resolve_citekey(rp, args.citekey, ui=ui, exit_on_fail=True)
+    citekey = resolve_citekey(rp, conf, args.citekey, ui=ui, exit_on_fail=True)
     paper = rp.pull_paper(citekey)
 
     coder = EnDecoder()
diff --git a/pubs/commands/export_cmd.py b/pubs/commands/export_cmd.py
index 2bbe01d..b316efc 100644
--- a/pubs/commands/export_cmd.py
+++ b/pubs/commands/export_cmd.py
@@ -46,7 +46,7 @@ def command(conf, args):
     if len(args.citekeys) < 1:
         papers = rp.all_papers()
     else:
-        for key in resolve_citekey_list(repo=rp, citekeys=args.citekeys, ui=ui, exit_on_fail=True):
+        for key in resolve_citekey_list(rp, conf, args.citekeys, ui=ui, exit_on_fail=True):
             papers.append(rp.pull_paper(key))
 
     bib = {}
diff --git a/pubs/commands/note_cmd.py b/pubs/commands/note_cmd.py
index 9466566..04c7eba 100644
--- a/pubs/commands/note_cmd.py
+++ b/pubs/commands/note_cmd.py
@@ -23,7 +23,7 @@ def command(conf, args):
 
     ui = get_ui()
     rp = repo.Repository(conf)
-    citekey = resolve_citekey(rp, args.citekey, ui=ui, exit_on_fail=True)
+    citekey = resolve_citekey(rp, conf, args.citekey, ui=ui, exit_on_fail=True)
     notepath = rp.databroker.real_notepath(citekey, rp.conf['main']['note_extension'])
     if args.append is None:
         ui.edit_file(notepath, temporary=False)
diff --git a/pubs/commands/remove_cmd.py b/pubs/commands/remove_cmd.py
index e09039c..e19211c 100644
--- a/pubs/commands/remove_cmd.py
+++ b/pubs/commands/remove_cmd.py
@@ -25,7 +25,7 @@ def command(conf, args):
     force = args.force
     rp = repo.Repository(conf)
 
-    keys = resolve_citekey_list(repo=rp, citekeys=args.citekeys, ui=ui, exit_on_fail=True)
+    keys = resolve_citekey_list(rp, conf, args.citekeys, ui=ui, exit_on_fail=True)
     plural = 's' if len(keys) > 1 else ''
 
     if force is None:
diff --git a/pubs/commands/rename_cmd.py b/pubs/commands/rename_cmd.py
index af14c4f..3461250 100644
--- a/pubs/commands/rename_cmd.py
+++ b/pubs/commands/rename_cmd.py
@@ -26,7 +26,7 @@ def command(conf, args):
     rp = repo.Repository(conf)
 
     # TODO: here should be a test whether the new citekey is valid
-    key = resolve_citekey(repo=rp, citekey=args.citekey, ui=ui, exit_on_fail=True)
+    key = resolve_citekey(rp, conf, args.citekey, ui=ui, exit_on_fail=True)
     paper = rp.pull_paper(key)
     rp.rename_paper(paper, args.new_citekey)
     ui.message("The '{}' citekey has been renamed into '{}'".format(
diff --git a/pubs/commands/tag_cmd.py b/pubs/commands/tag_cmd.py
index 78357c3..c12bf8f 100644
--- a/pubs/commands/tag_cmd.py
+++ b/pubs/commands/tag_cmd.py
@@ -55,7 +55,9 @@ def _parse_tag_seq(s):
             if last != 0:
                 raise ValueError('could not match tag expression')
         else:
-            tags.append(s[last:(m.start())])
+            tag = s[last:(m.start())]
+            if len(tag) > 0:
+                tags.append(s[last:(m.start())])
         last = m.start()
     if last == len(s):
         raise ValueError('could not match tag expression')
@@ -89,7 +91,7 @@ def command(conf, args):
     else:
         not_citekey = False
         try:
-            citekeyOrTag = resolve_citekey(repo=rp, citekey=citekeyOrTag, ui=ui, exit_on_fail=True)
+            citekeyOrTag = resolve_citekey(rp, conf, citekeyOrTag, ui=ui, exit_on_fail=True)
         except SystemExit:
             not_citekey = True
         if not not_citekey:
diff --git a/pubs/commands/url_cmd.py b/pubs/commands/url_cmd.py
index 7ac7b7f..224da7f 100644
--- a/pubs/commands/url_cmd.py
+++ b/pubs/commands/url_cmd.py
@@ -22,7 +22,7 @@ def command(conf, args):
     ui = get_ui()
     rp = repo.Repository(conf)
 
-    for key in resolve_citekey_list(rp, args.citekey, ui=ui, exit_on_fail=False):
+    for key in resolve_citekey_list(rp, conf, args.citekey, ui=ui, exit_on_fail=False):
         try:
             paper = rp.pull_paper(key)
             url = paper.bibdata['url']
diff --git a/pubs/utils.py b/pubs/utils.py
index 9b93aa3..120edfd 100644
--- a/pubs/utils.py
+++ b/pubs/utils.py
@@ -7,7 +7,7 @@ from . import color
 from . import pretty
 
 
-def resolve_citekey(repo, citekey, ui=None, exit_on_fail=True):
+def resolve_citekey(repo, conf, citekey, ui=None, exit_on_fail=True):
     """Check that a citekey exists, or autocompletes it if not ambiguous.
         :returns found citekey
     """
@@ -29,22 +29,23 @@ def resolve_citekey(repo, citekey, ui=None, exit_on_fail=True):
     elif citekey not in citekeys:
         if ui is not None:
             citekeys = sorted(citekeys)
-            ui.error("Be more specific; '{}' matches multiples "
-                     "citekeys:".format(citekey))
+            msg = ["Be more specific; '{}' matches multiples citekeys:".format(citekey)]
             for c in citekeys:
                 p = repo.pull_paper(c)
-                ui.message('    {}'.format(pretty.paper_oneliner(p, max_authors=conf['main']['max_authors'])))
+                paper_str = pretty.paper_oneliner(p, max_authors=conf['main']['max_authors'])
+                msg.append('    {}'.format(paper_str))
+            ui.error('\n'.join(msg))
             if exit_on_fail:
                 ui.exit()
     return citekey
 
 
-def resolve_citekey_list(repo, citekeys, ui=None, exit_on_fail=True):
+def resolve_citekey_list(repo, conf, citekeys, ui=None, exit_on_fail=True):
     shutdown = False
     keys = []
     for key in citekeys:
         try:
-            keys.append(resolve_citekey(repo, key, ui, exit_on_fail))
+            keys.append(resolve_citekey(repo, conf, key, ui=ui, exit_on_fail=exit_on_fail))
         except SystemExit:
             shutdown = exit_on_fail
 
diff --git a/tests/fake_env.py b/tests/fake_env.py
index 41d22d7..1d1865f 100644
--- a/tests/fake_env.py
+++ b/tests/fake_env.py
@@ -9,7 +9,7 @@ import dotdot
 
 from pyfakefs import fake_filesystem, fake_filesystem_unittest
 
-from pubs.p3 import input, _fake_stdio, _get_fake_stdio_ucontent
+from pubs.p3 import input
 from pubs import content, filebroker, uis
 
 # code for fake fs
@@ -29,29 +29,6 @@ original_exception_handler = uis.InputUI.handle_exception
 locale.setlocale(locale.LC_ALL, '')
 
 
-# capture output
-
-def capture(f, verbose=False):
-    """Capture the stdout and stderr output.
-
-    Useful for comparing the output with the expected one during tests.
-
-    :param f:        The function to capture output from.
-    :param verbose:  If True, print call will still display their outputs.
-                     If False, they will be silenced.
-
-    """
-    def newf(*args, **kwargs):
-        old_stderr, old_stdout = sys.stderr, sys.stdout
-        sys.stdout = _fake_stdio(additional_out=old_stdout if verbose else None)
-        sys.stderr = _fake_stdio(additional_out=old_stderr if verbose else None)
-        try:
-            return f(*args, **kwargs), _get_fake_stdio_ucontent(sys.stdout), _get_fake_stdio_ucontent(sys.stderr)
-        finally:
-            sys.stderr, sys.stdout = old_stderr, old_stdout
-    return newf
-
-
 # Test helpers
 
 # automating input
diff --git a/tests/test_note_append.py b/tests/test_note_append.py
index c3009f2..32eebee 100644
--- a/tests/test_note_append.py
+++ b/tests/test_note_append.py
@@ -46,7 +46,7 @@ class TestNoteAppend(DataCommandTestCase):
         #   * Pass the command split into a command and its args to
         #     execute_cmdsplit, which is called by execute_cmds:
         cmd_split = ['pubs', 'note', 'Page99', '-a', 'xxx yyy']
-        self.execute_cmdsplit(cmd_split, expected_out=None, expected_err=None)
+        self.execute_cmd_capture(cmd_split, expected_out=None, expected_err=None)
         note_lines.append('xxx yyy')
         self.assertFileContentEqual(fin_notes, self._get_note_content(note_lines))
 
diff --git a/tests/test_usecase.py b/tests/test_usecase.py
index 891d9cc..ba94559 100644
--- a/tests/test_usecase.py
+++ b/tests/test_usecase.py
@@ -17,6 +17,7 @@ import dotdot
 import fake_env
 import mock_requests
 
+
 from pubs import pubs_cmd, color, content, uis, p3, endecoder
 from pubs.config import conf
 
@@ -118,14 +119,12 @@ class CommandTestCase(fake_env.TestFakeFs):
                 input.as_global()
                 try:
                     if capture_output:
-                        actual_out = self.execute_cmdsplit(
-                            actual_cmd.split(), expected_out, expected_err)
+                        actual_out = self.execute_cmd_capture(actual_cmd.split(), expected_out, expected_err)
                         outs.append(color.undye(actual_out))
                     else:
                         pubs_cmd.execute(actual_cmd.split())
                 except fake_env.FakeInput.UnexpectedInput:
-                    self.fail('Unexpected input asked by command: {}.'.format(
-                        actual_cmd))
+                    self.fail('Unexpected input asked by command: {}.'.format(actual_cmd))
             return outs
         except SystemExit as exc:
             exc_class, exc, tb = sys.exc_info()
@@ -145,21 +144,25 @@ class CommandTestCase(fake_env.TestFakeFs):
             pass
         return s
 
-    def execute_cmdsplit(self, actual_cmdlist, expected_out, expected_err):
-        """Run a single command, which has been split into a list containing cmd and args"""
-        capture_wrap = fake_env.capture(pubs_cmd.execute,
-                                        verbose=PRINT_OUTPUT)
-        _, stdout, stderr = capture_wrap(actual_cmdlist)
-        actual_out = self.normalize(stdout)
-        actual_err = self.normalize(stderr)
+    def execute_cmd_capture(self, cmd, expected_out, expected_err):
+        """Run a single command, captures the output and and stderr and compare it to the expected ones"""
+        sys_stdout, sys_stderr = sys.stdout, sys.stderr
+        sys.stdout = p3._fake_stdio(additional_out=sys_stdout if PRINT_OUTPUT else None)
+        sys.stderr = p3._fake_stdio(additional_out=sys_stderr if PRINT_OUTPUT else None)
+
+        try:
+            pubs_cmd.execute(cmd)
+        finally:
+            # capturing output even if exception was raised.
+            self.captured_stdout = self.normalize(p3._get_fake_stdio_ucontent(sys.stdout))
+            self.captured_stderr = self.normalize(p3._get_fake_stdio_ucontent(sys.stderr))
+            sys.stderr, sys.stdout = sys_stderr, sys_stdout
+
         if expected_out is not None:
-            self.assertEqual(p3.u_maybe(actual_out), p3.u_maybe(expected_out))
+            self.assertEqual(p3.u_maybe(self.captured_stdout), p3.u_maybe(expected_out))
         if expected_err is not None:
-            self.assertEqual(p3.u_maybe(actual_err), p3.u_maybe(expected_err))
-        return actual_out
-
-    def tearDown(self):
-        pass
+            self.assertEqual(p3.u_maybe(self.captured_stderr), p3.u_maybe(expected_err))
+        return self.captured_stdout
 
     def update_config(self, config_update, path=None):
         """Allow to set the config parameters. Must have done a `pubs init` beforehand."""
@@ -624,6 +627,7 @@ class TestTag(DataCommandTestCase):
         with self.assertRaises(FakeSystemExit):
             self.execute_cmds(cmds)
 
+
 class TestURL(DataCommandTestCase):
 
     def setUp(self):
@@ -1126,6 +1130,21 @@ class TestUsecase(DataCommandTestCase):
         self.execute_cmds(cmds, capture_output=True)
 #        self.assertEqual(correct, self.execute_cmds(cmds, capture_output=True))
 
+    def test_ambiguous_citekey(self):
+        cmds = ['pubs init',
+                'pubs add data/pagerank.bib',
+                'pubs add data/pagerank.bib', # now we have Page99 and Page99a
+                'pubs edit Page',
+                ]
+        output = '\n'.join(["error: Be more specific; 'Page' matches multiples citekeys:",
+                            "    [Page99] Page, Lawrence et al. \"The PageRank Citation Ranking: Bringing Order to the Web.\" (1999) ",
+                            "    [Page99a] Page, Lawrence et al. \"The PageRank Citation Ranking: Bringing Order to the Web.\" (1999) \n"])
+
+        with self.assertRaises(FakeSystemExit):
+            self.execute_cmds(cmds)
+
+        self.assertEqual(self.captured_stderr, output)
+
 
 
 @ddt.ddt