> apt install libghc-xmonad-dev Reading package lists... DoneBuilding dependency tree Reading state information... DoneSome packages could not be installed. This may mean that you haverequested an impossible situation or if you are using the unstabledistribution that some required packages have not yet been createdor been moved out of Incoming.The following information may help to resolve the situation:The following packages have unmet dependencies: libghc-xmonad-dev : Depends: libghc-x11-dev-1.9-c01e0 but it is not installable Depends: libghc-base-dev-4.10.1.0-35a7f but it is not installable Depends: libghc-containers-dev-0.5.10.2-cc496 but it is not installable Depends: libghc-data-default-dev-0.7.1.1-17f03 but it is not installable Depends: libghc-directory-dev-1.3.0.2-60cb0 but it is not installable Depends: libghc-extensible-exceptions-dev-0.1.1.4-74508 but it is not installable Depends: libghc-filepath-dev-1.4.1.2-f4919 but it is not installable Depends: libghc-mtl-dev-2.2.2-ada79 but it is not installable Depends: libghc-process-dev-1.6.1.0-df30c but it is not installable Depends: libghc-setlocale-dev-1.0.0.6-823d2 but it is not installable Depends: libghc-unix-dev-2.7.2.2-1e3ca but it is not installable Depends: libghc-utf8-string-dev-1.0.1.1-e0ce7 but it is not installable Recommends: libghc-xmonad-contrib-dev but it is not going to be installedE: Unable to correct problems, you have held broken packages.
# apt policy libghc-xmonad-contrib-devlibghc-xmonad-contrib-dev: Installiert: 0.17.0-1 Installationskandidat: 0.17.0-1 Versionstabelle: *** 0.17.0-1 500 500 http://ftp.de.debian.org/debian unstable/main amd64 Packages 100 /var/lib/dpkg/status
# apt policy libghc-xmonad-devlibghc-xmonad-dev: Installiert: 0.17.0-2 Installationskandidat: 0.17.0-2 Versionstabelle: *** 0.17.0-2 500 500 http://ftp.de.debian.org/debian unstable/main amd64 Packages 100 /var/lib/dpkg/status