From d8ccca178b35752efa67369442cca58972264fdd Mon Sep 17 00:00:00 2001
From: ddelange <14880945+ddelange@users.noreply.github.com>
Date: Fri, 20 Dec 2019 02:25:57 +0100
Subject: [PATCH 1/4] After least versions, the package with least dependencies
 is chosen

---
 mixology/version_solver.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/mixology/version_solver.py b/mixology/version_solver.py
index bb56383..e02a204 100644
--- a/mixology/version_solver.py
+++ b/mixology/version_solver.py
@@ -324,10 +324,13 @@ def _next_term_to_try(self):  # type: () -> Optional[Term]
 
         # Prefer packages with as few remaining versions as possible,
         # so that if a conflict is necessary it's forced quickly.
+        # at a tie, the package with least dependencies is chosen
         def _get_min(term):
-            return len(
-                self._source.versions_for(term.package, term.constraint.constraint)
+            versions = self._source.versions_for(
+                term.package, term.constraint.constraint
             )
+            deps = self._source.dependencies_for(term.package, versions[0])
+            return len(versions), len(deps)
 
         if len(unsatisfied) == 1:
             term = unsatisfied[0]

From 831150f721b9c98c161d1742099b4ba5f36db4ee Mon Sep 17 00:00:00 2001
From: david <14880945+ddelange@users.noreply.github.com>
Date: Sun, 22 Dec 2019 13:56:42 +0100
Subject: [PATCH 2/4] Fix test: if no versions available, keep old behaviour

---
 mixology/version_solver.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mixology/version_solver.py b/mixology/version_solver.py
index e02a204..5503100 100644
--- a/mixology/version_solver.py
+++ b/mixology/version_solver.py
@@ -329,7 +329,7 @@ def _get_min(term):
             versions = self._source.versions_for(
                 term.package, term.constraint.constraint
             )
-            deps = self._source.dependencies_for(term.package, versions[0])
+            deps = self._source.dependencies_for(term.package, versions[0]) if versions else []
             return len(versions), len(deps)
 
         if len(unsatisfied) == 1:

From 6906aa77117a68609cbede539e87576d89c29be6 Mon Sep 17 00:00:00 2001
From: ddelange <14880945+ddelange@users.noreply.github.com>
Date: Mon, 30 Dec 2019 11:39:58 +0100
Subject: [PATCH 3/4] Run black

---
 mixology/version_solver.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mixology/version_solver.py b/mixology/version_solver.py
index 5503100..b1bfad8 100644
--- a/mixology/version_solver.py
+++ b/mixology/version_solver.py
@@ -329,7 +329,11 @@ def _get_min(term):
             versions = self._source.versions_for(
                 term.package, term.constraint.constraint
             )
-            deps = self._source.dependencies_for(term.package, versions[0]) if versions else []
+            deps = (
+                self._source.dependencies_for(term.package, versions[0])
+                if versions
+                else []
+            )
             return len(versions), len(deps)
 
         if len(unsatisfied) == 1:

From b1fb5c82ebaff8300c1adc7c05ac7a681dfbb0af Mon Sep 17 00:00:00 2001
From: ddelange <14880945+ddelange@users.noreply.github.com>
Date: Mon, 30 Dec 2019 19:45:15 +0100
Subject: [PATCH 4/4] Fix test

---
 tests/test_unsolvable.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/test_unsolvable.py b/tests/test_unsolvable.py
index 90084aa..b93f8fd 100644
--- a/tests/test_unsolvable.py
+++ b/tests/test_unsolvable.py
@@ -26,9 +26,9 @@ def test_no_version_that_matches_combined_constraints(source):
     source.add("shared", "3.5.0")
 
     error = """\
-Because foo (1.0.0) depends on shared (>=2.0.0 <3.0.0)
- and no versions of shared match >=2.9.0,<3.0.0, foo (1.0.0) requires shared (>=2.0.0,<2.9.0).
-And because bar (1.0.0) depends on shared (>=2.9.0 <4.0.0), bar (1.0.0) is incompatible with foo (1.0.0).
+Because no versions of shared match >=2.9.0,<3.0.0
+ and bar (1.0.0) depends on shared (>=2.9.0 <4.0.0), bar (1.0.0) requires shared (>=3.0.0,<4.0.0).
+And because foo (1.0.0) depends on shared (>=2.0.0 <3.0.0), bar (1.0.0) is incompatible with foo (1.0.0).
 So, because root depends on both foo (1.0.0) and bar (1.0.0), version solving failed."""
 
     check_solver_result(source, error=error)