[sonic_installer]: Improve exception handling: introduce notes.

Signed-off-by: Nazarii Hnydyn <nazariig@nvidia.com>

sonic_installer/common.py

@@ -46,10 +46,15 @@ def run_command_or_raise(argv, raise_exception=True, capture=True):
 
     stdout = subprocess.PIPE if capture else None
     proc = subprocess.Popen(argv, text=True, stdout=stdout)
-    out, _ = proc.communicate()
+    out, err = proc.communicate()
 
     if proc.returncode != 0 and raise_exception:
-        raise SonicRuntimeException("Failed to run command '{0}'".format(argv))
+        sre = SonicRuntimeException("Failed to run command '{0}'".format(argv))
+        if out:
+            sre.add_note("\nSTDOUT:\n{}".format(out.rstrip("\n")))
+        if err:
+            sre.add_note("\nSTDERR:\n{}".format(err.rstrip("\n")))
+        raise sre
 
     if out is not None:
         out = out.rstrip("\n")

sonic_installer/exception.py

@@ -5,4 +5,15 @@
 class SonicRuntimeException(Exception):
     """SONiC Runtime Excpetion class used to report SONiC related errors
     """
-    pass
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.notes = []
+
+    def __str__(self):
+        msg = super().__str__()
+        if self.notes:
+            msg += "\n" + "\n".join(self.notes)
+        return msg
+
+    def add_note(self, note):
+        self.notes.append(note)