testimage: retrieve ptests directory when ptests fail

TESTIMAGE_FAILED_QA_ARTIFACTS is set with a default, minimal list of files
to retrieve whenever a runtime test fails.
Add ptests directory to the list so we can get ptests artifacts (eg: logs)
whenever a ptest fails. By appending the ptest directory with the
multiconfig component in the path, only failing ptests will lead to
corresponding ptest artifacts retrieval, instead of all ptests artifacts
retrieval. While doing this addition, reinforce default value using "="
operator to make sure to get the default list in any case.

(From OE-Core rev: 9357ab6c47f0a0a7000cb18358bc9775fd54e1f7)

Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/testimage.bbclass

@@ -22,11 +22,14 @@ TESTIMAGE_AUTO ??= "0"
 # each entry in it, if artifact pointed by path description exists on target,
 # it will be retrieved onto host
 
-TESTIMAGE_FAILED_QA_ARTIFACTS ??= "\
+TESTIMAGE_FAILED_QA_ARTIFACTS = "\
     ${localstatedir}/log \
     ${sysconfdir}/version \
     ${sysconfdir}/os-release"
 
+# If some ptests are run and fail, retrieve corresponding directories
+TESTIMAGE_FAILED_QA_ARTIFACTS += "${@bb.utils.contains('DISTRO_FEATURES', 'ptest', '${libdir}/${MCNAME}/ptest', '', d)}"
+
 # You can set (or append to) TEST_SUITES in local.conf to select the tests
 # which you want to run for your target.
 # The test names are the module names in meta/lib/oeqa/runtime/cases.

meta/recipes-core/images/core-image-ptest.bb

@@ -42,4 +42,3 @@ python () {
     if not d.getVar("MCNAME"):
         raise bb.parse.SkipRecipe("No class extension set")
 }
-