kdepimlibs, kdepim-runtime and kdepim recently fail to build in our docker containers with a message like this:
```
Generating moc_testsearchplugin.cpp
/work/source/kdepimlibs/akonadi/tests/testsearchplugin/testsearchplugin.h:30: Error: Undefined interface
AUTOGEN: error: process for /work/build/kdepimlibs/akonadi/tests/testsearchplugin/moc_testsearchplugin.cpp failed:
/work/source/kdepimlibs/akonadi/tests/testsearchplugin/testsearchplugin.h:30: Error: Undefined interface
moc failed...
akonadi/tests/testsearchplugin/CMakeFiles/akonadi_test_searchplugin_automoc.dir/build.make:57: recipe for target 'akonadi/tests/testsearchplugin/CMakeFiles/akonadi_test_searchpl
ugin_automoc' failed
make[2]: *** [akonadi/tests/testsearchplugin/CMakeFiles/akonadi_test_searchplugin_automoc] Error 1
CMakeFiles/Makefile2:12997: recipe for target 'akonadi/tests/testsearchplugin/CMakeFiles/akonadi_test_searchplugin_automoc.dir/all' failed
make[1]: *** [akonadi/tests/testsearchplugin/CMakeFiles/akonadi_test_searchplugin_automoc.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
```
The root cause of this is that moc is invoked with incorrect include paths (try make VERBOSE=1 to find how moc is invoked:):
```
/usr/lib64/qt4/bin/moc-qt4 \
-I/work/build/kdepimlibs/akonadi/tests/testsearchplugin \
-I/work/build/kdepimlibs/akonadi/tests \
-I/work/build/kdepimlibs/akonadi \
-I/work/build/kdepimlibs/akonadi/kmime \
-I/work/build/kdepimlibs/kmime \
-I/work/source/kdepimlibs/akonadi/tests/testsearchplugin \
-I/work/source/kdepimlibs/akonadi \
-I/work/source/kdepimlibs \
-I/work/build/kdepimlibs \
-I/work/install/include/KDE \
-I/usr/include/KDE \
-I/usr/include/phonon \
-I/usr/include/QtXmlPatterns \
-I/usr/include/QtXml \
-I/usr/include/QtWebKit \
-I/usr/include/QtUiTools \
-I/usr/include/QtTest \
-I/usr/include/QtSvg \
-I/usr/include/QtSql \
-I/usr/include/QtScriptTools \
-I/usr/include/QtScript \
-I/usr/include/QtOpenGL \
-I/usr/include/QtNetwork \
-I/usr/include/QtMultimedia \
-I/usr/include/QtHelp \
-I/usr/include/QtDesigner \
-I/usr/include/QtDeclarative \
-I/usr/include/QtDBus \
-I/usr/include/Qt3Support \
-I/usr/include/QtGui \
-I/usr/include/QtCore \
-I/usr/include/Qt \
-I/usr/lib64/qt4/mkspecs/default \
-I/work/install/include/akonadi/private \
-I/usr/include \
-I/usr/include \
-DKDE4_CMAKE_TOPLEVEL_DIR_LENGTH=12 \
-DKDE_DEFAULT_DEBUG_AREA=5250 \
-DKDE_DEPRECATED_WARNINGS \
-DQT_NO_CAST_TO_ASCII \
-DQT_NO_STL \
-DQT_USE_QSTRINGBUILDER \
-D_BSD_SOURCE \
-D_DEFAULT_SOURCE \
-D_REENTRANT \
-D_XOPEN_SOURCE=500 \
-o /work/build/kdepimlibs/akonadi/tests/testsearchplugin/moc_testsearchplugin.cpp /work/source/kdepimlibs/akonadi/tests/testsearchplugin/testsearchplugin.h
```
The problem is that /work/install/include is missing from the include paths as it get's stripped from the viable paths somehow.
It seems cmake is the culprit, but I'm not entirely sure.