support/testing: use again the default BR2_BACKUP_SITE

This reverts commit 559bb33ae71dd2358ca2314ccb24b56cc3809fc1, which
was disabling BR2_BACKUP_SITE in our tests with the following
reasoning:

    support/testing: do not use s.b.o

    Currently, the runtime tests will use the sources.buildroot.org backup
    mirror, which is the default setup.

    However, in some cases we do not want to use the backup site, because we
    want to ensure that the download actually works.

    This is the case for vendored packages, like cargo or golang packages,
    for whbich we want to check that gthe download still works when we
    update the rust or go versions, or when our download helpers change.

    So, disable the use of the backup site in all runtime tests, and drop
    the no-longer needed special cases.

    Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
    Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

However, not using the backup site is causing a LOT of random failures
in Gitlab CI, making the results barely usable. Since it's more
important to get real failures than random ones due to download
issues, let's re-enable BR2_BACKUP_SITE in our testing infrastructure.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Romain Naour <romain.naour@smile.fr>

support/testing/infra/basetest.py

@@ -37,7 +37,6 @@ class BRConfigTest(unittest.TestCase):
         super(BRConfigTest, self).__init__(names)
         self.testname = self.__class__.__name__
         self.builddir = self.outputdir and os.path.join(self.outputdir, self.testname)
-        self.config += '\nBR2_BACKUP_SITE=""\n'
         self.config += '\nBR2_DL_DIR="{}"\n'.format(self.downloaddir)
         self.config += "\nBR2_JLEVEL={}\n".format(self.jlevel)
 

support/testing/tests/download/test_git.py

@@ -7,7 +7,10 @@ import infra
 
 
 class GitTestBase(infra.basetest.BRConfigTest):
-    config = ""
+    config = \
+        """
+        BR2_BACKUP_SITE=""
+        """
     gitremotedir = infra.filepath("tests/download/git-remote")
     gitremote = None
 

support/testing/tests/download/test_gitforge.py

@@ -5,7 +5,10 @@ import infra
 
 
 class GitforgeTestBase(infra.basetest.BRConfigTest):
-    config = ""
+    config = \
+        """
+        BR2_BACKUP_SITE=""
+        """
 
     def setUp(self):
         super(GitforgeTestBase, self).setUp()

support/testing/tests/download/test_ssh.py

@@ -7,7 +7,9 @@ import infra
 
 
 class SSHTestBase(infra.basetest.BRConfigTest):
-    config = infra.basetest.MINIMAL_CONFIG
+    config = infra.basetest.MINIMAL_CONFIG + '''
+BR2_BACKUP_SITE=""
+'''
     sshd_test_dir = infra.filepath("tests/download/sshd")
     sshd = None
 

support/testing/tests/package/test_rust.py

@@ -70,6 +70,7 @@ class TestRustVendoring(infra.basetest.BRConfigTest):
         BR2_PACKAGE_RIPGREP=y
         BR2_PACKAGE_PYTHON3=y
         BR2_PACKAGE_PYTHON_CRYPTOGRAPHY=y
+        BR2_BACKUP_SITE=""
         """
 
     def setUp(self):