gather: Use fresh cache for each sequence of fus runs

Each depsolved tree will be using its own cache for fus. This should
still allow for faster loading of metadata after first iteration, but
should prevent errors from using cached files meant for another variant
or architecture. The cache is deleted after the last iteration.

JIRA: COMPOSE-3959
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

pungi/phases/gather/methods/method_hybrid.py

@@ -27,7 +27,7 @@ from pungi import multilib_dnf
 from pungi.module_util import Modulemd
 from pungi.arch import get_valid_arches, tree_arch_to_yum_arch
 from pungi.phases.gather import _mk_pkg_map
-from pungi.util import get_arch_variant_data, pkg_is_debug
+from pungi.util import get_arch_variant_data, pkg_is_debug, temp_dir
 from pungi.wrappers import fus
 from pungi.wrappers.comps import CompsWrapper
 
@@ -210,7 +210,11 @@ class GatherMethodHybrid(pungi.phases.gather.method.GatherMethodBase):
         # strings.
         filters = [_fmt_pkg(*p) for p in filter_packages]
 
-        nvrs, out_modules = self.run_solver(variant, arch, packages, platform, filters)
+        cache_prefix = "fus-cache-%s-%s-%s-" % (self.compose.compose_id, variant, arch)
+        with temp_dir(prefix=cache_prefix) as cache_dir:
+            nvrs, out_modules = self.run_solver(
+                variant, arch, packages, platform, filters, cache_dir=cache_dir
+            )
         filter_modules(variant, arch, out_modules)
         return expand_packages(
             self._get_pkg_map(arch),
@@ -228,7 +232,7 @@ class GatherMethodHybrid(pungi.phases.gather.method.GatherMethodBase):
             repos.append(pkgset.paths[self.arch])
         return repos
 
-    def run_solver(self, variant, arch, packages, platform, filter_packages):
+    def run_solver(self, variant, arch, packages, platform, filter_packages, cache_dir):
         repos = self.get_repos()
         results = set()
         result_modules = set()
@@ -263,6 +267,7 @@ class GatherMethodHybrid(pungi.phases.gather.method.GatherMethodBase):
             # useless for us anyway).
             env = os.environ.copy()
             env["G_MESSAGES_PREFIXED"] = ""
+            env["XDG_CACHE_HOME"] = cache_dir
             self.compose.log_debug("[BEGIN] Running fus")
             run(cmd, logfile=logfile, show_cmd=True, env=env)
             output, out_modules = fus.parse_output(logfile)

tests/test_gather_method_hybrid.py

@@ -27,12 +27,13 @@ class NamedMock(mock.Mock):
 
 
 class TestMethodHybrid(helpers.PungiTestCase):
+    @mock.patch("pungi.phases.gather.methods.method_hybrid.temp_dir")
     @mock.patch("pungi.phases.gather.methods.method_hybrid.CompsWrapper")
     @mock.patch("pungi.phases.gather.get_lookaside_repos")
     @mock.patch("pungi.phases.gather.methods.method_hybrid.expand_groups")
     @mock.patch("pungi.phases.gather.methods.method_hybrid.expand_packages")
     @mock.patch("pungi.phases.gather.methods.method_hybrid.get_platform")
-    def test_call_method(self, gp, ep, eg, glr, CW):
+    def test_call_method(self, gp, ep, eg, glr, CW, td):
         compose = helpers.DummyCompose(self.topdir, {})
         m = hybrid.GatherMethodHybrid(compose)
         m.run_solver = mock.Mock(return_value=(mock.Mock(), mock.Mock()))
@@ -73,9 +74,14 @@ class TestMethodHybrid(helpers.PungiTestCase):
                     set(["pkg", "foo", "bar", ("prep", "noarch")]),
                     gp.return_value,
                     [],
+                    cache_dir=td.return_value.__enter__.return_value,
                 )
             ],
         )
+        self.assertIn(
+            [mock.call(prefix="fus-cache-Test-20151203.0.t-Server-x86_64-")],
+            td.mock_calls,
+        )
         self.assertEqual(
             ep.call_args_list,
             [
@@ -331,6 +337,7 @@ class TestRunSolver(HelperMixin, helpers.PungiTestCase):
             [],
             platform="pl",
             filter_packages=[("foo", None)],
+            cache_dir="/cache",
         )
 
         self.assertEqual(res[0], set())
@@ -386,6 +393,7 @@ class TestRunSolver(HelperMixin, helpers.PungiTestCase):
             [],
             platform="pl",
             filter_packages=["foo"],
+            cache_dir="/cache",
         )
 
         self.assertEqual(res, (set([("p-1-1", "x86_64", frozenset())]), set(["m1"])))
@@ -426,6 +434,7 @@ class TestRunSolver(HelperMixin, helpers.PungiTestCase):
             [("pkg", None)],
             platform=None,
             filter_packages=[],
+            cache_dir="/cache",
         )
 
         six.assertCountEqual(self, res[0], po.return_value[0])
@@ -481,6 +490,7 @@ class TestRunSolver(HelperMixin, helpers.PungiTestCase):
             [("pkg", None)],
             platform=None,
             filter_packages=[],
+            cache_dir="/cache",
         )
 
         six.assertCountEqual(
@@ -553,6 +563,7 @@ class TestRunSolver(HelperMixin, helpers.PungiTestCase):
             [("pkg", None)],
             platform=None,
             filter_packages=["foo"],
+            cache_dir="/cache",
         )
 
         six.assertCountEqual(self, res[0], final)
@@ -640,6 +651,7 @@ class TestRunSolver(HelperMixin, helpers.PungiTestCase):
             [("pkg-devel", None), ("foo", None)],
             platform=None,
             filter_packages=[],
+            cache_dir="/cache",
         )
 
         six.assertCountEqual(
@@ -762,6 +774,7 @@ class TestRunSolver(HelperMixin, helpers.PungiTestCase):
             [("pkg-devel", None), ("foo", None)],
             platform=None,
             filter_packages=[],
+            cache_dir="/cache",
         )
 
         six.assertCountEqual(