diff --git a/src/plugins/projectexplorer/projecttree.cpp b/src/plugins/projectexplorer/projecttree.cpp
index df02418238c..fc3175a1bcf 100644
--- a/src/plugins/projectexplorer/projecttree.cpp
+++ b/src/plugins/projectexplorer/projecttree.cpp
@@ -273,8 +273,8 @@ void ProjectTree::sessionAndTreeChanged()
 
 void ProjectTree::collapseAll()
 {
-    if (m_focusForContextMenu)
-        m_focusForContextMenu->collapseAll();
+    if (auto w = Utils::findOrDefault(s_instance->m_projectTreeWidgets, &ProjectTree::hasFocus))
+        w->collapseAll();
 }
 
 void ProjectTree::updateExternalFileWarning()
diff --git a/src/shared/clang/clang_installation.pri b/src/shared/clang/clang_installation.pri
index cb9478f0acf..514226a0bb0 100644
--- a/src/shared/clang/clang_installation.pri
+++ b/src/shared/clang/clang_installation.pri
@@ -117,6 +117,15 @@ isEmpty(LLVM_VERSION) {
         "LLVM/Clang version >= 6.0.0 required, version provided: $$LLVM_VERSION")
     LLVM_VERSION =
 } else {
+    # CLANG-UPGRADE-CHECK: Remove suppression if this warning is resolved.
+    gcc {
+        # GCC6 shows full version (6.4.0), while GCC7 and up show only major version (8)
+        GCC_VERSION = $$system("$$QMAKE_CXX -dumpversion")
+        GCC_MAJOR_VERSION = $$section(GCC_VERSION, ., 0, 0)
+        # GCC8 warns about memset/memcpy for types with copy ctor. Clang has some of these.
+        greaterThan(GCC_MAJOR_VERSION, 7):QMAKE_CXXFLAGS += -Wno-class-memaccess
+    }
+
     LLVM_LIBDIR = $$quote($$system($$llvm_config --libdir, lines))
     LLVM_BINDIR = $$quote($$system($$llvm_config --bindir, lines))
     LLVM_INCLUDEPATH = $$system($$llvm_config --includedir, lines)
diff --git a/tests/system/shared/welcome.py b/tests/system/shared/welcome.py
index dc48424a5ca..f6338a91fa5 100644
--- a/tests/system/shared/welcome.py
+++ b/tests/system/shared/welcome.py
@@ -67,7 +67,6 @@ def switchToSubMode(subModeLabel):
     return frameAndLabelFound
 
 def findExampleOrTutorial(tableView, regex, verbose=False):
-    model = tableView.model()
     children = __childrenOfType__(tableView, 'QModelIndex')
     for child in children:
         if re.match(regex, str(child.text)):
diff --git a/tests/system/suite_WELP/tst_WELP03/test.py b/tests/system/suite_WELP/tst_WELP03/test.py
index 347d37ec1a3..86cc8c12dc9 100644
--- a/tests/system/suite_WELP/tst_WELP03/test.py
+++ b/tests/system/suite_WELP/tst_WELP03/test.py
@@ -106,7 +106,7 @@ def main():
                     "Verifying: The project is shown in 'Edit' mode.")
         invokeContextMenuOnProject('2dpainting', 'Close Project "2dpainting"')
         navTree = waitForObject(":Qt Creator_Utils::NavigationTreeView")
-        res = waitFor("navTree.model().rowCount(navTree.rootIndex()) == 0", 2000)
+        waitFor("navTree.model().rowCount(navTree.rootIndex()) == 0", 2000)
         test.verify(not checkIfObjectItemExists(":Qt Creator_Utils::NavigationTreeView", "2dpainting"),
                     "Verifying: The first example is closed.")
     # clean up created packaging directories
@@ -132,7 +132,7 @@ def main():
                     "Verifying: The project is shown in 'Edit' mode while old project isn't.")
         invokeContextMenuOnProject('addressbook', 'Close Project "addressbook"')
         navTree = waitForObject(":Qt Creator_Utils::NavigationTreeView")
-        res = waitFor("navTree.model().rowCount(navTree.rootIndex()) == 0", 2000)
+        waitFor("navTree.model().rowCount(navTree.rootIndex()) == 0", 2000)
         test.verify(not checkIfObjectItemExists(":Qt Creator_Utils::NavigationTreeView", "addressbook"),
                     "Verifying: The second example is closed.")
     # clean up created packaging directories