oeqa: selftest: context: run tests serially if testtools/subunit modules are not found

If testtools and/or subunit modules are not found we get the following backtrace
(example for testtools):

  NOTE: Starting bitbake server...
  Traceback (most recent call last):
    File "<..>/poky/scripts/oe-selftest", line 60, in
  <module>
      ret = main()
    File "<..>/poky/scripts/oe-selftest", line 47, in main
      results = args.func(logger, args)
    File "<..>/poky/meta/lib/oeqa/selftest/context.py",
  line 391, in run
      rc = self._internal_run(logger, args)
    File "<..>/poky/meta/lib/oeqa/selftest/context.py",
  line 377, in _internal_run
      rc = self.tc.runTests(**self.tc_kwargs['run'])
    File "<..>/poky/meta/lib/oeqa/selftest/context.py",
  line 161, in runTests
      return super(OESelftestTestContext, self).runTests(processes, skips)
    File "<..>/poky/meta/lib/oeqa/core/context.py", line
  91, in runTests
      result = self.runner.run(self.prepareSuite(self.suites, processes))
    File "<..>/poky/meta/lib/oeqa/selftest/context.py",
  line 154, in prepareSuite
      from oeqa.core.utils.concurrencytest import ConcurrentTestSuite
    File
  "<..>/poky/meta/lib/oeqa/core/utils/concurrencytest.py",
  line 22, in <module>
      import testtools
  ModuleNotFoundError: No module named 'testtools'

Fix this by adding a custom callback on -j/--num-processes parameter to
check testtools and subunit modules. Fallback to serial testing if
missing. This strategy is already used in sdk/context.py

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/meta/lib/oeqa/selftest/context.py b/meta/lib/oeqa/selftest/context.py
index 57844b289a..99186175e5 100644
--- a/meta/lib/oeqa/selftest/context.py
+++ b/meta/lib/oeqa/selftest/context.py
@@ -194,8 +194,23 @@ class OESelftestTestContextExecutor(OETestContextExecutor):
         parser.add_argument('-R', '--skip-tests', required=False, action='store',
                 nargs='+', dest="skips", default=None,
                 help='Skip the tests specified. Format should be <module>[.<class>[.<test_method>]]')
+
+        def check_parallel_support(parameter):
+            if not parameter.isdigit():
+                import argparse
+                raise argparse.ArgumentTypeError("argument -j/--num-processes: invalid int value: '%s' " % str(parameter))
+
+            processes = int(parameter)
+            if processes:
+                try:
+                    import testtools, subunit
+                except ImportError:
+                    print("Failed to import testtools or subunit, the testcases will run serially")
+                    processes = None
+            return processes
+
         parser.add_argument('-j', '--num-processes', dest='processes', action='store',
-                type=int, help="number of processes to execute in parallel with")
+                type=check_parallel_support, help="number of processes to execute in parallel with")
 
         parser.add_argument('-t', '--select-tag', dest="select_tags",
                 action='append', default=None,