Modifications to Cylc entry point to allow coverage collection in Cylc Review

cylc/flow/scripts/cylc.py

@@ -580,9 +580,13 @@ def pycoverage(cmd_args):  # pragma: no cover
     import cylc.flow
     import coverage
     from pathlib import Path
+    import signal
 
     # the cylc working directory
-    cylc_wc = Path(cylc.flow.__file__).parents[2]
+    if 'CYLC_COVERAGE_BASE' in os.environ:
+        cylc_wc = Path(os.environ['CYLC_COVERAGE_BASE'])
+    else:
+        cylc_wc = Path(cylc.flow.__file__).parents[2]
 
     # initiate coverage
     try:
@@ -604,13 +608,7 @@ def pycoverage(cmd_args):  # pragma: no cover
             '\n\n*****************************\n\n'
         ) from exc
 
-    # start the coverage running
-    cov.start()
-    try:
-        # yield control back to cylc, return once the command exits
-        yield
-    finally:
-        # stop the coverage and save the data
+    def cov_stop(*a, **k):
         cov.stop()
         cov.save()
         if cylc_coverage == '2':
@@ -619,6 +617,16 @@ def pycoverage(cmd_args):  # pragma: no cover
                     '$ cylc ' + (' '.join(cmd_args) + '\n'),
                 )
 
+    # start the coverage running
+    cov.start()
+    signal.signal(signal.SIGINT, cov_stop)
+    try:
+        # yield control back to cylc, return once the command exits
+        yield
+    finally:
+        # stop the coverage and save the data
+        cov_stop()
+
 
 def get_arg_parser():
     parser = argparse.ArgumentParser(add_help=False)