[Bug]: kmail: No Header Style plugin found - IID mismatch between messagelib and kdepim-addons

Open

#457 opened on May 24, 2026 1 comment 0 reactions 3 assignees Claimed by @vnepogodin View on GitHub

bug

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Description

### Package name

messagelib

### Package version

26.04.1-1.1

### Issue type

Packaging error (wrong deps, missing files, etc.)

### Description

## Bug description
KMail does not show message headers (sender, subject, date).
The View → Headers menu is empty.

## System
- CachyOS with KDE Plasma
- kmail 26.04.1-1.1 (cachyos-extra-v3)
- kdepim-addons 26.04.1-1.1 (cachyos-extra-v3)
- messagelib 26.04.1-1.1 (cachyos-extra-v3)

## Root cause
Running `kmail 2>&1` shows:
org.kde.pim.messageviewer: No Header Style plugin found !

With QT_DEBUG_PLUGINS=1, the headerstyle plugins are found and loaded,
but immediately unloaded.

The IID mismatch is the cause:
- libKPim6MessageViewer.so.6 expects IID: `org.kde.pim.messageviewer`
- kdepim-addons headerstyle plugins expose IID: `org.kde.KPluginFactory`

Verified with:
strings /usr/lib/libKPim6MessageViewer.so.6 | grep "org.kde"
→ org.kde.pim.messageviewer

strings /usr/lib/qt6/plugins/pim6/messageviewer/headerstyle/messageviewer_fancyheaderstyleplugin.so | grep "org.kde"
→ org.kde.KPluginFactory

Either messagelib or kdepim-addons needs to be recompiled so the IIDs match.

### Steps to reproduce