From 96e054aea15827bbfca2cf3982056b4d29410535 Mon Sep 17 00:00:00 2001
From: Kenneth Reitz <me@kennethreitz.org>
Date: Sun, 11 Mar 2018 14:29:34 -0400
Subject: [PATCH] fix #1670

---
 pipenv/patched/piptools/resolver.py | 40 +++++++++++++++++------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/pipenv/patched/piptools/resolver.py b/pipenv/patched/piptools/resolver.py
index c9c6bd85..dc8d2d7a 100755
--- a/pipenv/patched/piptools/resolver.py
+++ b/pipenv/patched/piptools/resolver.py
@@ -306,23 +306,31 @@ class Resolver(object):
         log.debug('  {:25} requires {}'.format(format_requirement(ireq),
                                                ', '.join(sorted(dependency_strings, key=lambda s: s.lower())) or '-'))
         from notpip._vendor.packaging.markers import InvalidMarker
+
         for dependency_string in dependency_strings:
-            individual_dependencies = [dep.strip() for dep in dependency_string.split(', ')]
-            cleaned_deps = []
-            for dep in individual_dependencies:
-                tokens = [token.strip() for token in dep.split(';')]
-                cleaned_tokens = []
-                markers = []
-                if len(tokens) == 1:
-                    cleaned_deps.append(tokens[0])
-                    continue
-                markers = list(set(tokens[1:]))
-                cleaned_tokens.append(tokens[0])
-                if markers:
-                    cleaned_tokens.extend(markers)
-                cleaned_deps.append('; '.join(cleaned_tokens))
-            dependency_string = ', '.join(set(cleaned_deps))
-            yield InstallRequirement.from_line(dependency_string, constraint=ireq.constraint)
+
+            try:
+                individual_dependencies = [dep.strip() for dep in dependency_string.split(', ')]
+                cleaned_deps = []
+                for dep in individual_dependencies:
+                    tokens = [token.strip() for token in dep.split(';')]
+                    cleaned_tokens = []
+                    markers = []
+                    if len(tokens) == 1:
+                        cleaned_deps.append(tokens[0])
+                        continue
+                    markers = list(set(tokens[1:]))
+                    cleaned_tokens.append(tokens[0])
+                    if markers:
+                        cleaned_tokens.extend(markers)
+                    cleaned_deps.append('; '.join(cleaned_tokens))
+                _dependency_string = ', '.join(set(cleaned_deps))
+
+                yield InstallRequirement.from_line(_dependency_string, constraint=ireq.constraint)
+            except InvalidMarker:
+                yield InstallRequirement.from_line(dependency_string, constraint=ireq.constraint)
+
+
 
 
     def reverse_dependencies(self, ireqs):