nixpkgs/pkgs/desktops/plasma-5/libkscreen/libkscreen-backends-path.patch

Index: libkscreen-5.9.4/src/backendmanager.cpp
===================================================================
--- libkscreen-5.9.4.orig/src/backendmanager.cpp
+++ libkscreen-5.9.4/src/backendmanager.cpp
@@ -172,14 +172,11 @@ QFileInfo BackendManager::preferredBackend(const QString &backend)
 QFileInfoList BackendManager::listBackends()
 {
     // Compile a list of installed backends first
-    const QString backendFilter = QStringLiteral("KSC_*");
-    const QStringList paths = QCoreApplication::libraryPaths();
-    QFileInfoList finfos;
-    for (const QString &path : paths) {
-        const QDir dir(path + QLatin1String("/kf5/kscreen/"), backendFilter, QDir::SortFlags(QDir::QDir::Name), QDir::NoDotAndDotDot | QDir::Files);
-        finfos.append(dir.entryInfoList());
-    }
-    return finfos;
+    const QDir dir(QLatin1String(NIXPKGS_LIBKSCREEN_BACKENDS),
+                   QStringLiteral("KSC_*"),
+                   QDir::SortFlags(QDir::QDir::Name),
+                   QDir::NoDotAndDotDot | QDir::Files);
+    return dir.entryInfoList();
 }
 
 KScreen::AbstractBackend *BackendManager::loadBackendPlugin(QPluginLoader *loader, const QString &name, const QVariantMap &arguments)