commit 3df2bb87f1da5f02db2efef52010a523376ebe70
Author: Federico Ressi <fressi@redhat.com>
Date:   Fri Oct 9 14:25:54 2020 +0200

    Add TOX_PYDEV_DEBUG env variable to run_tests.py
    
    Add new env variable to handle test cases
    execution when debugging test cases under a
    debugger by using testools.run runner.
    
    Change-Id: Ia6ec38e6471d93dd98c3fef17e66e9187c666c9d

diff --git a/tools/common.py b/tools/common.py
index f87f734..432b372 100644
--- a/tools/common.py
+++ b/tools/common.py
@@ -22,6 +22,8 @@ import tempfile
 
 
 LOG = logging.getLogger(__name__)
+BASH_EXECUTABLE = '/bin/bash'
+PYTHON_EXECUTABLE = os.environ.get('PYTHON', sys.executable)
 
 
 def get_logger(name):
@@ -52,6 +54,7 @@ def execute(command, *args, **kwargs):
     capture_stdout = kwargs.pop('capture_stdout', True)
     universal_newlines = kwargs.pop('universal_newlines', True)
     check = kwargs.pop('check', True)
+    shell = kwargs.pop('shell', '/bin/bash')
 
     if args or kwargs:
         command = command.format(*args, **kwargs)
@@ -59,7 +62,34 @@ def execute(command, *args, **kwargs):
 
     stdout = capture_stdout and subprocess.PIPE or None
 
-    result = subprocess.run(['/bin/bash', '-x', '-c', command],
+    if shell:
+        command_line = [shell, '-x', '-c', command]
+    else:
+        command_line = shlex.split(command)
+
+    LOG.info(f"Execute: {command_line}")
+    result = subprocess.run(command_line,
+                            stdout=stdout, shell=False,
+                            universal_newlines=universal_newlines)
+    if check:
+        result.check_returncode()
+    return result.stdout
+
+
+def execute_python(command, *args, **kwargs):
+    capture_stdout = kwargs.pop('capture_stdout', True)
+    universal_newlines = kwargs.pop('universal_newlines', True)
+    check = kwargs.pop('check', True)
+    interpreter = kwargs.pop('interpreter', PYTHON_EXECUTABLE)
+
+    if args or kwargs:
+        command = command.format(*args, **kwargs)
+    command = command.strip()
+    command_line = [interpreter] + shlex.split(command)
+
+    stdout = capture_stdout and subprocess.PIPE or None
+    LOG.info(f"Execute: {command_line}")
+    result = subprocess.run(command_line,
                             stdout=stdout, shell=False,
                             universal_newlines=universal_newlines)
     if check:
diff --git a/tools/run_tests.py b/tools/run_tests.py
index 248379e..9847a6d 100755
--- a/tools/run_tests.py
+++ b/tools/run_tests.py
@@ -21,8 +21,6 @@ import sys
 import subprocess
 
 
-
-
 TOP_DIR = os.path.dirname(os.path.dirname(__file__))
 if TOP_DIR not in sys.path:
     sys.path.insert(0, TOP_DIR)
@@ -53,6 +51,10 @@ TOX_REPORT_XML = os.environ.get(
 
 TOX_RUN_TESTS_TIMEOUT = float(os.environ.get('TOX_RUN_TESTS_TIMEOUT') or 0.)
 
+TOX_PYDEV_DEBUG = bool(
+    os.environ.get('TOX_PYDEV_DEBUG', 'false').lower() in
+    ['true', 'yes', '1'])
+
 
 def main():
     common.setup_logging()
@@ -75,6 +77,10 @@ def run_tests():
     cleanup_report_dir()
     log_environ()
 
+    if TOX_PYDEV_DEBUG:
+        debug_test_cases()
+        return True
+
     succeeded = True
     try:
         run_test_cases()
@@ -149,6 +155,12 @@ def log_tests_results():
                    check=False)
 
 
+def debug_test_cases():
+    common.execute_python('-m testtools.run {posargs}',
+                          posargs=common.get_posargs(),
+                          capture_stdout=False)
+
+
 def run_test_cases():
     common.execute('stestr run --slowest {posargs}',
                    posargs=common.get_posargs(),