fixes #14.

.gitignore

@@ -79,3 +79,4 @@ include/
 .eggs/
 lib/
 .pydistutils.cfg
+.coverage*

tests/test_packages_full.py

@@ -31,6 +31,21 @@ def test_install(tmpdir):
     assert code == 0
 
 
+def test_package_cache(tmpdir):
+    """ don't event attempt to call pip, if a package already exists. """
+    tmpdir.join("ubuild.py").write(URANIUM_PY)
+    execute_script(
+        "uranium_standalone", "--uranium-dir", URANIUM_SOURCE_ROOT,
+        cwd=tmpdir.strpath
+    )
+    code, out, err = execute_script(
+        "uranium_standalone", "--uranium-dir", URANIUM_SOURCE_ROOT,
+        cwd=tmpdir.strpath
+    )
+    assert "Requirement already satisified" not in str(out)
+    assert code == 0
+
+
 def test_update(tmpdir):
     """ update should update versions to the latest. """
     hard_version = URANIUM_PY_UPDATE.format(',version="==1.3.1"')

uranium/packages/__init__.py

@@ -92,7 +92,6 @@ def _is_package_already_installed(name, version):
                 package_name += version
             pkg_resources.get_distribution(package_name)
             return True
-        except (pkg_resources.VersionConflict,
-                pkg_resources.DistributionNotFound):
+        except Exception:
             pass
         return False