yocto-compat-layer: fix also other command invocations

In commit 5b9ac62ab535d, one place was fixed where a command was
invoked such that failures caused double stack traces and stderr was
lost. The same problem also occurs elsewhere, triggered for example by
a layer with parsing problems.

Now a new utility method is used instead of repeating the code.

(From OE-Core rev: b6c72c0d169473e2626938be2ee59f850624612e)

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/compatlayer/__init__.py

@@ -4,6 +4,7 @@
 # Released under the MIT license (see COPYING.MIT)
 
 import os
+import subprocess
 from enum import Enum
 
 class LayerType(Enum):
@@ -199,8 +200,20 @@ def add_layer(bblayersconf, layer, layers, logger):
 
     return True
 
+def check_command(error_msg, cmd):
+    '''
+    Run a command under a shell, capture stdout and stderr in a single stream,
+    throw an error when command returns non-zero exit code. Returns the output.
+    '''
+
+    p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    output, _ = p.communicate()
+    if p.returncode:
+        msg = "%s\nCommand: %s\nOutput:\n%s" % (error_msg, cmd, output.decode('utf-8'))
+        raise RuntimeError(msg)
+    return output
+
 def get_signatures(builddir, failsafe=False):
-    import subprocess
     import re
 
     # some recipes needs to be excluded like meta-world-pkgdata
@@ -214,12 +227,8 @@ def get_signatures(builddir, failsafe=False):
     if failsafe:
         cmd += '-k '
     cmd += '-S none world'
-    p = subprocess.Popen(cmd, shell=True,
-                         stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-    output, _ = p.communicate()
-    if p.returncode:
-        msg = "Generating signatures failed. This might be due to some parse error and/or general layer incompatibilities.\nCommand: %s\nOutput:\n%s" % (cmd, output.decode('utf-8'))
-        raise RuntimeError(msg)
+    check_command('Generating signatures failed. This might be due to some parse error and/or general layer incompatibilities.',
+                  cmd)
     sigs_file = os.path.join(builddir, 'locked-sigs.inc')
 
     sig_regex = re.compile("^(?P<task>.*:.*):(?P<hash>.*) .$")

scripts/lib/compatlayer/cases/common.py

@@ -2,9 +2,8 @@
 # Released under the MIT license (see COPYING.MIT)
 
 import os
-import subprocess
 import unittest
-from compatlayer import get_signatures, LayerType
+from compatlayer import get_signatures, LayerType, check_command
 from compatlayer.case import OECompatLayerTestCase
 
 class CommonCompatLayer(OECompatLayerTestCase):
@@ -20,26 +19,12 @@ class CommonCompatLayer(OECompatLayerTestCase):
                 msg="Layer contains README file but is empty.")
 
     def test_parse(self):
-        try:
-            output = subprocess.check_output('bitbake -p', shell=True,
-                    stderr=subprocess.PIPE)
-        except subprocess.CalledProcessError as e:
-            import traceback
-            exc = traceback.format_exc()
-            msg = 'Layer %s failed to parse.\n%s\n%s\n' % (self.tc.layer['name'],
-                    exc, e.output.decode('utf-8'))
-            raise RuntimeError(msg)
+        check_command('Layer %s failed to parse.' % self.tc.layer['name'],
+                      'bitbake -p')
 
     def test_show_environment(self):
-        try:
-            output = subprocess.check_output('bitbake -e', shell=True,
-                    stderr=subprocess.PIPE)
-        except subprocess.CalledProcessError as e:
-            import traceback
-            exc = traceback.format_exc()
-            msg = 'Layer %s failed to show environment.\n%s\n%s\n' % \
-                    (self.tc.layer['name'], exc, e.output.decode('utf-8'))
-            raise RuntimeError(msg)
+        check_command('Layer %s failed to show environment.' % self.tc.layer['name'],
+                      'bitbake -e')
 
     def test_signatures(self):
         if self.tc.layer['type'] == LayerType.SOFTWARE: