Small fix to prevent this test from interfering with others.

lib/spack/spack/test/unit_install.py

@@ -26,16 +26,16 @@
 import itertools
 
 import spack
-test_install = __import__("spack.cmd.test-install", 
+test_install = __import__("spack.cmd.test-install",
     fromlist=["BuildId", "create_test_output", "TestResult"])
 
 class MockOutput(object):
     def __init__(self):
         self.results = {}
-    
+
     def add_test(self, buildId, passed=True, buildInfo=None):
         self.results[buildId] = passed
-    
+
     def write_to(self, stream):
         pass
 
@@ -45,14 +45,14 @@ def __init__(self, name, version, hashStr=None):
         self.name = name
         self.version = version
         self.hash = hashStr if hashStr else hash((name, version))
-    
+
     def traverse(self, order=None):
-        allDeps = itertools.chain.from_iterable(i.traverse() for i in 
+        allDeps = itertools.chain.from_iterable(i.traverse() for i in
             self.dependencies.itervalues())
         return set(itertools.chain([self], allDeps))
-    
+
     def dag_hash(self):
-        return self.hash 
+        return self.hash
 
     def to_yaml(self):
         return "<<<MOCK YAML {0}>>>".format(test_install.BuildId(self).stringId())
@@ -75,47 +75,52 @@ class UnitInstallTest(unittest.TestCase):
 
     def setUp(self):
         super(UnitInstallTest, self).setUp()
-        
+
         pkgX.installed = False
         pkgY.installed = False
 
+        self.saved_db = spack.db
         pkgDb = MockPackageDb({specX:pkgX, specY:pkgY})
         spack.db = pkgDb
 
+
     def tearDown(self):
         super(UnitInstallTest, self).tearDown()
-        
+
+        spack.db = self.saved_db
+
     def test_installing_both(self):
         mo = MockOutput()
-        
+
         pkgX.installed = True
         pkgY.installed = True
         test_install.create_test_output(specX, [specX, specY], mo, getLogFunc=test_fetch_log)
-        
-        self.assertEqual(mo.results, 
-            {bIdX:test_install.TestResult.PASSED, 
+
+        self.assertEqual(mo.results,
+            {bIdX:test_install.TestResult.PASSED,
             bIdY:test_install.TestResult.PASSED})
 
+
     def test_dependency_already_installed(self):
         mo = MockOutput()
-        
+
         pkgX.installed = True
         pkgY.installed = True
         test_install.create_test_output(specX, [specX], mo, getLogFunc=test_fetch_log)
-        
+
         self.assertEqual(mo.results, {bIdX:test_install.TestResult.PASSED})
 
     #TODO: add test(s) where Y fails to install
 
+
 class MockPackageDb(object):
     def __init__(self, init=None):
         self.specToPkg = {}
         if init:
             self.specToPkg.update(init)
-        
+
     def get(self, spec):
         return self.specToPkg[spec]
 
 def test_fetch_log(path):
     return []
-