It looks like the experimental version of kmymoney is no longer installable in sid:
$ LANG=C sudo apt install libkf5newstuffcore5 Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libalkimia5-7 libaqbanking-data libaqbanking35 libaqbanking35-plugins libaqebics0 libaqhbci24 libaqofxconnect7 libgwengui-cpp0 libgwengui-qt5-0 libgwenhywfar-data libgwenhywfar60 libkchart2 libkchart2-l10n libkf5holidays-data libkf5holidays5 libkf5webkit5 libktoblzcheck1v5 libofx7 libqt5sensors5 libqt5webkit5 libre2-4 libsqlcipher0 libxmlsec1-gcrypt libxmlsec1-gnutls Use 'sudo apt autoremove' to remove them. The following additional packages will be installed: kio libkf5attica5 libkf5bookmarks-data libkf5bookmarks5 libkf5completion-data libkf5completion5 libkf5configwidgets-data libkf5configwidgets5 libkf5iconthemes-data libkf5iconthemes5 libkf5jobwidgets-data libkf5jobwidgets5 libkf5kcmutils-data libkf5kcmutils5 libkf5kiofilewidgets5 libkf5quickaddons5 libkf5solid5 libkf5solid5-data libkf5textwidgets-data libkf5textwidgets5 libkf5wallet-bin libkf5wallet-data libkf5wallet5 libkf5widgetsaddons-data libkf5widgetsaddons5 libkf5xmlgui-data libkf5xmlgui5 libkwalletbackend5-5 libqt5core5a libqt5dbus5 libqt5designer5 libqt5gui5 libqt5multimedia5 libqt5multimedia5-plugins libqt5multimediawidgets5 libqt5network5 libqt5opengl5 libqt5positioning5 libqt5printsupport5 libqt5qml5 libqt5quick5 libqt5quickcontrols2-5 libqt5quicktemplates2-5 libqt5quickwidgets5 libqt5script5 libqt5sensors5 libqt5sql5 libqt5sql5-sqlite libqt5svg5 libqt5test5 libqt5texttospeech5 libqt5waylandclient5 libqt5waylandcompositor5 libqt5webchannel5 libqt5webengine-data libqt5webengine5 libqt5webenginecore5 libqt5webenginewidgets5 libqt5webkit5 libqt5widgets5 libqt5xml5 python3-pyqt5 python3-pyqt5.qtwebchannel python3-pyqt5.qtwebengine qml-module-qtgraphicaleffects qml-module-qtquick-controls qml-module-qtquick-controls2 qml-module-qtquick-layouts qt5-gtk-platformtheme qtwayland5 telegram-desktop Suggested packages: qt5-qmltooling-plugins python3-pyqt5-dbg Recommended packages: libkf5iconthemes-bin qml-module-org-kde-newstuff libkf5xmlgui-bin The following packages will be REMOVED: kmymoney The following packages will be upgraded: kio libkf5attica5 libkf5bookmarks-data libkf5bookmarks5 libkf5completion-data libkf5completion5 libkf5configwidgets-data libkf5configwidgets5 libkf5iconthemes-data libkf5iconthemes5 libkf5jobwidgets-data libkf5jobwidgets5 libkf5kcmutils-data libkf5kcmutils5 libkf5kiofilewidgets5 libkf5newstuffcore5 libkf5quickaddons5 libkf5solid5 libkf5solid5-data libkf5textwidgets-data libkf5textwidgets5 libkf5wallet-bin libkf5wallet-data libkf5wallet5 libkf5widgetsaddons-data libkf5widgetsaddons5 libkf5xmlgui-data libkf5xmlgui5 libkwalletbackend5-5 libqt5core5a libqt5dbus5 libqt5designer5 libqt5gui5 libqt5multimedia5 libqt5multimedia5-plugins libqt5multimediawidgets5 libqt5network5 libqt5opengl5 libqt5positioning5 libqt5printsupport5 libqt5qml5 libqt5quick5 libqt5quickcontrols2-5 libqt5quicktemplates2-5 libqt5quickwidgets5 libqt5script5 libqt5sensors5 libqt5sql5 libqt5sql5-sqlite libqt5svg5 libqt5test5 libqt5texttospeech5 libqt5waylandclient5 libqt5waylandcompositor5 libqt5webchannel5 libqt5webengine-data libqt5webengine5 libqt5webenginecore5 libqt5webenginewidgets5 libqt5webkit5 libqt5widgets5 libqt5xml5 python3-pyqt5 python3-pyqt5.qtwebchannel python3-pyqt5.qtwebengine qml-module-qtgraphicaleffects qml-module-qtquick-controls qml-module-qtquick-controls2 qml-module-qtquick-layouts qt5-gtk-platformtheme qtwayland5 telegram-desktop