package_manager/ipk: do not pipe stderr to stdout

Some opkg commands print an error during cleanup when the tmp_dir
does not exist and an attempt is made to delete it. The error messages
are harmless and the opkg commands eventually succeed.
When these commands are run and stderr is piped to stdout, the error
messages may clobber the stdout and cause unexpected results while
parsing the output of the command. Therefore, when parsing the output
of a command, do not pipe stderr to stdout. Instead, capture stderr
and stdout separately, and upon success, send stderr to bb.note().

Signed-off-by: Shruthi Ravichandran <shruthi.ravichandran@ni.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 13 insertions, 10 deletions

diff --git a/meta/lib/oe/package_manager/ipk/__init__.py b/meta/lib/oe/package_manager/ipk/__init__.py
index 6fd2f021b6..7cbea0fa80 100644
--- a/meta/lib/oe/package_manager/ipk/__init__.py
+++ b/meta/lib/oe/package_manager/ipk/__init__.py
@@ -102,12 +102,14 @@ class OpkgDpkgPM(PackageManager):
         This method extracts the common parts for Opkg and Dpkg
         """
 
-        try:
-            output = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True).decode("utf-8")
-        except subprocess.CalledProcessError as e:
+        proc = subprocess.run(cmd, capture_output=True, encoding="utf-8", shell=True)
+        if proc.returncode:
             bb.fatal("Unable to list available packages. Command '%s' "
-                     "returned %d:\n%s" % (cmd, e.returncode, e.output.decode("utf-8")))
-        return opkg_query(output)
+                     "returned %d:\n%s" % (cmd, proc.returncode, proc.stderr))
+        elif proc.stderr:
+            bb.note("Command '%s' returned stderr: %s" % (cmd, proc.stderr))
+
+        return opkg_query(proc.stdout)
 
     def extract(self, pkg, pkg_info):
         """
@@ -445,15 +447,16 @@ class OpkgPM(OpkgDpkgPM):
         cmd = "%s %s --noaction install %s " % (self.opkg_cmd,
                                                 opkg_args,
                                                 ' '.join(pkgs))
-        try:
-            output = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True)
-        except subprocess.CalledProcessError as e:
+        proc = subprocess.run(cmd, capture_output=True, encoding="utf-8", shell=True)
+        if proc.returncode:
             bb.fatal("Unable to dummy install packages. Command '%s' "
-                     "returned %d:\n%s" % (cmd, e.returncode, e.output.decode("utf-8")))
+                     "returned %d:\n%s" % (cmd, proc.returncode, proc.stderr))
+        elif proc.stderr:
+            bb.note("Command '%s' returned stderr: %s" % (cmd, proc.stderr))
 
         bb.utils.remove(temp_rootfs, True)
 
-        return output
+        return proc.stdout
 
     def backup_packaging_data(self):
         # Save the opkglib for increment ipk image generation