oeqa: add output to subprocess exceptions

Out of the box subprocess.CalledProcessError.__str__() just displays the command
and exit code, which isn't very useful for debugging.

Add a function to oeqa.utils.subprocesstweak to monkey-patch __str__() so that
it can also display the value of stdout and stderr.

(From OE-Core rev: c55401ba1646202fa36e4973b05dbacaa146cb16)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 19 insertions, 9 deletions

diff --git a/meta/lib/oeqa/oetest.py b/meta/lib/oeqa/oetest.py
index a89bd117c0..1dad763ff1 100644
--- a/meta/lib/oeqa/oetest.py
+++ b/meta/lib/oeqa/oetest.py
@@ -135,15 +135,6 @@ class oeRuntimeTest(oeTest):
             if status != 0:
                 return status
 
-class OETestCalledProcessError(subprocess.CalledProcessError):
-    def __str__(self):
-        if hasattr(self, "stderr"):
-            return "Command '%s' returned non-zero exit status %d with output %s and stderr %s" % (self.cmd, self.returncode, self.output, self.stderr)
-        else:
-            return "Command '%s' returned non-zero exit status %d with output %s" % (self.cmd, self.returncode, self.output)
-
-subprocess.CalledProcessError = OETestCalledProcessError
-
 def getmodule(pos=2):
     # stack returns a list of tuples containg frame information
     # First element of the list the is current frame, caller is 1
diff --git a/meta/lib/oeqa/utils/subprocesstweak.py b/meta/lib/oeqa/utils/subprocesstweak.py
new file mode 100644
index 0000000000..1f7d11b55c
--- /dev/null
+++ b/meta/lib/oeqa/utils/subprocesstweak.py
@@ -0,0 +1,19 @@
+import subprocess
+
+class OETestCalledProcessError(subprocess.CalledProcessError):
+    def __str__(self):
+        def strify(o):
+            if isinstance(o, bytes):
+                return o.decode("utf-8", errors="replace")
+            else:
+                return o
+
+        s = "Command '%s' returned non-zero exit status %d" % (self.cmd, self.returncode)
+        if hasattr(self, "output") and self.output:
+            s = s + "\nStandard Output: " + strify(self.output)
+        if hasattr(self, "stderr") and self.stderr:
+            s = s + "\nStandard Error: " + strify(self.stderr)
+        return s
+
+def errors_have_output():
+    subprocess.CalledProcessError = OETestCalledProcessError