Looks like the cmake configure files do not work well for static build.  I built keepassx with 5.12.3 static build.  I worked if I used qmake to configure the build. But I got tons of linker errors if I used cmake.  It also worked for 5.12.3 default build even if I used cmake.

https://github.com/keepassx/keepassx

qlibrary_unix.cpp.text._ZN15QLibraryPrivate10unload_sysEv+0x1f): undefined reference to `dlclose'

qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlib6wakeUpEv+0x15): undefined reference to `g_main_context_wakeup'

qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x89): undefined reference to `g_source_destroy'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x95): undefined reference to `g_source_unref'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0xac): undefined reference to `g_source_destroy'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0xb8): undefined reference to `g_source_unref'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x11e): undefined reference to `g_source_remove_poll'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x1ec): undefined reference to `g_source_destroy'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x1f8): undefined reference to `g_source_unref'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x20f): undefined reference to `g_source_destroy'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x21b): undefined reference to `g_source_unref'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x22f): undefined reference to `g_main_context_pop_thread_default'
qeventdispatcher_glib.cpp.text._ZN20QEventDispatcherGlibD2Ev+0x238): undefined reference to `g_main_context_unref'

qpnghandler.cpp.text._ZN18QPngHandlerPrivate15readImageFormatEv+0x4f): undefined reference to `png_get_IHDR'
qpnghandler.cpp.text._ZN18QPngHandlerPrivate15readImageFormatEv+0xc5): undefined reference to `png_get_valid'
qpnghandler.cpp.text._ZN18QPngHandlerPrivate15readImageFormatEv+0xe9): undefined reference to `png_get_channels'
qpnghandler.cpp.text._ZN18QPngHandlerPrivate15readImageFormatEv+0x113): undefined reference to `png_get_PLTE'
qpnghandler.cpp.text._ZN18QPngHandlerPrivate15readImageFormatEv+0x13e): undefined reference to `png_get_valid'
qpnghandler.cpp.text._ZN18QPngHandlerPrivate15readImageFormatEv+0x176): undefined reference to `png_get_valid'
qpnghandler.cpp.text._ZN18QPngHandlerPrivate15readImageFormatEv+0x19e): undefined reference to `png_get_valid'

qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0x4b): undefined reference to `hb_unicode_funcs_create'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0x65): undefined reference to `hb_unicode_funcs_set_combining_class_func'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0x7c): undefined reference to `hb_unicode_funcs_set_eastasian_width_func'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0x93): undefined reference to `hb_unicode_funcs_set_general_category_func'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0xaa): undefined reference to `hb_unicode_funcs_set_mirroring_func'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0xc1): undefined reference to `hb_unicode_funcs_set_script_func'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0xd8): undefined reference to `hb_unicode_funcs_set_compose_func'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0xef): undefined reference to `hb_unicode_funcs_set_decompose_func'
qharfbuzzng.cpp.text._Z23hb_qt_get_unicode_funcsv+0x106): undefined reference to `hb_unicode_funcs_set_decompose_compatibility_func'