Problem: nothing provides 'libQt5Gui.so.5(Qt_5.15.5_PRIVATE_API)(64bit)' needed
by the to be installed libfm-qt11-1.1.0-1.5.x86_64
 Solution 1: do not install pcmanfm-qt-1.1.0-2.1.x86_64
 Solution 2: break libfm-qt11-1.1.0-1.5.x86_64 by ignoring some of its
dependencies

Looks like some packages aren't updated to pull in [new]
"libQt5Gui.so.5(Qt_5.15.6_PRIVATE_API)(64bit)" vs
"libQt5Gui.so.5(Qt_5.15.5_PRIVATE_API)(64bit)":

$ zypper search --details --provides
'libQt5Gui.so.5(Qt_5.15.6_PRIVATE_API)(64bit)'
Loading repository data...
Reading installed packages...

S | Name       | Type    | Version           | Arch   | Repository
--+------------+---------+-------------------+--------+----------------------
i | libQt5Gui5 | package | 5.15.6+kde177-1.1 | x86_64 | Main Repository (OSS)

Things don't look healthy in these places:

https://build.opensuse.org/package/show/openSUSE:Factory/libfm-qt
* "unresolvable: nothing provides libQt5Core.so.5(Qt_5.15.5_PRIVATE_API)(64bit)
needed by libQt5Xdg3"

https://build.opensuse.org/package/show/openSUSE:Factory/libqt5xdg
* "failed"
...
[   24s] CMake Error at
/usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
[   24s]   Could NOT find GLIB (missing: GLIB_GIO_UNIX_INCLUDE_DIR) (found
suitable
[   24s]   version "2.74.0", minimum required is "2.41.0")