Bug 354562

fyi

Truncated backtrace:
Thread no. 1 (10 frames)
 #0 QtPrivate::RefCount::ref at /usr/include/qt5/QtCore/qrefcount.h:54
 #1 QString::QString at /usr/include/qt5/QtCore/qstring.h:878
 #2 PackageKitResource::installedPackageId at ../../../../libmuon/backends/PackageKitBackend/PackageKitResource.cpp:68
 #3 PackageKitResource::availablePackageId at ../../../../libmuon/backends/PackageKitBackend/PackageKitResource.cpp:63
 #4 PKTransaction::start at ../../../../libmuon/backends/PackageKitBackend/PKTransaction.cpp:46
 #5 ResourcesModel::qt_static_metacall at moc_ResourcesModel.cpp:157
 #6 ResourcesModel::qt_metacall at moc_ResourcesModel.cpp:264
 #7 QQmlObjectOrGadget::metacall at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/qml/qqmlpropertycache.cpp:1689
 #8 CallMethod at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/jsruntime/qv4qobjectwrapper.cpp:1160
 #9 CallPrecise at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/jsruntime/qv4qobjectwrapper.cpp:1409

Could you try the following patch and tell me what's the added output?

diff --git a/libmuon/backends/PackageKitBackend/PackageKitResource.cpp b/libmuon/backends/PackageKitBackend/PackageKitResource.cpp
index f1ee811..3f51253 100644
--- a/libmuon/backends/PackageKitBackend/PackageKitResource.cpp
+++ b/libmuon/backends/PackageKitBackend/PackageKitResource.cpp
@@ -65,6 +65,7 @@ QString PackageKitResource::availablePackageId() const
 
 QString PackageKitResource::installedPackageId() const
 {
+    qDebug() << "installed" << m_packages;
     return m_packages[PackageKit::Transaction::InfoInstalled].first();
 }

First crash: (after Abe install):
  Remove transaction: "abe" with 1 transactions running
  installed QMap()

Second crash: (after Abe remove):
  installed QMap((1, ("abe;1.1-25.fc22;x86_64;installed:fedora")))
  Remove transaction: "abe" with 1 transactions running
  installed QMap()

To clarify: https://www.youtube.com/watch?v=6qa7sZ6t8Uo

I suspect one complication here may be no (or stale) packageKit metadata cache (may explain why I cannot reproduce the problems seen here personally).

May be worth :
* try running 'pkmon' while performing this test, to see what packagekitd is doing
* prior to testing muon, run: pkcon refresh force

Created attachment 95225 [details]
pkmon output

the problem seem be caused by PKTransaction::cleanup() 
exactly this rows:

PackageKit::Transaction* t = PackageKit::Daemon::resolve(resource()->packageName(), PackageKit::Transaction::FilterArch | PackageKit::Transaction::FilterLast);
qobject_cast<PackageKitResource*>(resource())->resetPackageIds();
connect(t, SIGNAL(package(PackageKit::Transaction::Info,QString,QString)), resource(), SLOT(addPackageId(PackageKit::Transaction::Info, QString,QString)));

the "package" signal isn't emitted and the m_packages map remain empty

The question is why?

Git commit a24e495c2eea95e76b1389bdffaf27e30d7e273a by Aleix Pol.
Committed on 03/11/2015 at 15:54.
Pushed by apol into branch 'Plasma/5.4'.

Batch resource package id's

This way we make sure it stays consistent

M  +12   -4    libmuon/backends/PackageKitBackend/PKTransaction.cpp
M  +3    -2    libmuon/backends/PackageKitBackend/PackageKitResource.cpp
M  +3    -1    libmuon/backends/PackageKitBackend/PackageKitResource.h

http://commits.kde.org/muon/a24e495c2eea95e76b1389bdffaf27e30d7e273a

last commit don't fix this, the package signal isn't emitted and the setPackages() pass a empty QMap to PackageKitResource, consequently muon crash

if you apply this path:
--- a/libmuon/backends/PackageKitBackend/PKTransaction.cpp	2015-11-03 18:17:55.094175121 +0100
+++ b/libmuon/backends/PackageKitBackend/PKTransaction.cpp	2015-11-03 18:55:18.620076119 +0100
@@ -103,13 +103,18 @@
         m_trans = nullptr;
     }
     PackageKit::Transaction* t = PackageKit::Daemon::resolve(resource()->packageName(), PackageKit::Transaction::FilterArch | PackageKit::Transaction::FilterLast);
+    
+    connect(t, SIGNAL(errorCode(PackageKit::Transaction::Error,QString)), this, SLOT(errorFound(PackageKit::Transaction::Error,QString)));
+    
     connect(t, &PackageKit::Transaction::package, t, [t](PackageKit::Transaction::Info info, const QString& packageId) {
+        qDebug() << "package signal emitted";
         QMap<PackageKit::Transaction::Info, QStringList> packages = t->property("packages").value<QMap<PackageKit::Transaction::Info, QStringList>>();
         packages[info].append(packageId);
         t->setProperty("packages", qVariantFromValue(packages));
     });
 
     connect(t, &PackageKit::Transaction::finished, t, [t, this](PackageKit::Transaction::Exit status, uint runtime){
+        qDebug() << "finished signal emitted";
         QMap<PackageKit::Transaction::Info, QStringList> packages = t->property("packages").value<QMap<PackageKit::Transaction::Info, QStringList>>();
         qobject_cast<PackageKitResource*>(resource())->setPackages(packages);
         setStatus(Transaction::DoneStatus);

in output I receive only "finished signal emitted" and no error message

Can you confirm that `pkcon resolve <package>` where package is the package you're trying to un/install returns something?

yes, it return the package info:
      
Installato      abe-1.1-25.fc22.x86_64 (installed:fedora)                       Scrolling, platform-jumping, ancient pyramid exploring game

Created attachment 95313 [details]
fix patch

This patch fix problem but I'm not sure this is a correct solution

Git commit 456c5a03b5397f58a4915c40eca3e5ca7225f794 by Aleix Pol.
Committed on 05/11/2015 at 15:47.
Pushed by apol into branch 'Plasma/5.4'.

Fix package resolution after un/installing

Thanks a lot to Elia Devito for the patch!

M  +1    -1    libmuon/backends/PackageKitBackend/PKTransaction.cpp

http://commits.kde.org/muon/456c5a03b5397f58a4915c40eca3e5ca7225f794

I have the same problem when I try to install plasma-widget-cwp widget (it doesn't appear in installed softwares) and in "add widget".
I also have the same problem hen I try to install weather-widget a part of necessary packages were not installed.