plasma-desktop compiled deep into its tree (105 packages cooked) and failed on
applets/taskmanager/backend.h:16: fatal error: netwm.h
because adding the X11 libraries made find_package(X11) succeed, so
CMakeLists.txt:211 set HAVE_X11=1 -- and the code then legitimately includes
KWindowSystem's X11-only headers, which our KWindowSystem does not install.
I tried the coherent fix first: KWINDOWSYSTEM_X11=ON. It fails because Qt here
is built without the xcb platform:
src/platforms/xcb/kxerrorhandler_p.h:15: fatal error: private/qtx11extras_p.h
That header ships only with Qt's X11 support, so enabling KWindowSystem X11
cascades into rebuilding qtbase with the entire xcb plugin stack. Too large to
start mid-build; reverted with the reason recorded at the flag.
So HAVE_X11=1 asserts "Qt/KDE X11 integration is available", which is false
here. Forced to 0 -- the honest value -- and the gating script compiles those
paths out. The X11 libraries remain, because they ARE required: X11 is TYPE
REQUIRED in plasma-desktop and libxcb is needed unconditionally.
Also promotes xcb-util-keysyms and xcb-util-wm (built and staged:
libxcb-keysyms.a, libxcb-icccm.a, libxcb-ewmh.a), which KWindowSystem X11 would
need and which are cheap to have available.
vasilito
68a4a45e5b