Having trouble with an unmet dependencies loop using apt

Question

I'm trying to do some stuff with packages on a newly upgraded 18.04 (from 16.04), but I keep getting blocked by a bunch of packages with unmet dependencies. Here's the output whenever I try to install a package:

adamthedog@adam-linux:~$ sudo apt install *any package*
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 libasan2-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libasan4-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libatomic1-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libcilkrts5-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libgcc1-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libgomp1-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libstdc++6-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libubsan0-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 ubuntu-app-launch : Depends: upstart (>= 1.13) but it is not installable
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

If I try to do sudo apt --fix-broken install, I get

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  account-plugin-facebook account-plugin-flickr account-plugin-google alsa-firmware alsa-firmware-loaders alsa-tools apparmor-easyprof-ubuntu apt-config-icons-large apt-config-icons-large-hidpi arctican-plugins-vst artyfx buteo-sync-plugins-contacts-google buteo-syncfw
  cgmanager click click-apparmor cmake-data content-hub cpp-5-arm-linux-gnueabihf cryptsetup-bin dexed-vst discover discover-data distrho-plugin-ports-vst drmr drowaudio-plugins-vst dssi-example-plugins dssi-utils easyssp-vst emacs24-bin-common emacs24-common
  emacs24-common-non-dfsg emacs24-el esound-common fabla firebird2.5-common-doc fonts-horai-umefont fonts-unfonts-core foo-yc20-vst freerdp-x11 fxload g++-5-arm-linux-gnueabihf gcc-5-arm-linux-gnueabihf gcc-5-arm-linux-gnueabihf-base gcc-5-base:i386 gcc-5-cross-base
  gcc-6-base:i386 gir1.2-accounts-1.0 gir1.2-click-0.4 gir1.2-javascriptcoregtk-3.0 gir1.2-signon-1.0 gir1.2-webkit-3.0 gnome-characters gnome-icon-theme-symbolic gnome-keyring-pkcs11:i386 gnome-packagekit-data gnome-weather golang-1.6 golang-1.6-doc golang-1.6-go
  golang-1.6-race-detector-runtime golang-1.6-src gstreamer0.10-gnomevfs gxvoxtonebender infamous-plugins jackass kde-style-qtcurve-qt4 kde-style-qtcurve-qt5 kdepim-doc klangfalter-vst kubuntu-restricted-addons kubuntu-restricted-extras libaccount-plugin-1.0-0
  libaccount-plugin-generic-oauth libaccount-plugin-google libappstream3 libappstreamqt1 libasan2-armhf-cross libbind9-140 libblas-common libboost-atomic1.58.0 libboost-chrono1.58.0 libboost-date-time1.58.0 libboost-iostreams1.58.0 libboost-log1.58.0
  libboost-python1.58.0 libboost-random1.58.0 libboost-serialization1.58.0 libboost-signals1.58.0 libbotan-1.10-1 libbuteosyncfw5-0 libc6-dev:i386 libcamel-1.2-54 libcapnp-0.5.3 libcfitsio2 libcgal11v5 libcgmanager0 libchromaprint0 libclang1-3.6 libclick-0.4-0
  libclutter-gst-2.0-0 libconfig-file-perl libconfuse-common libcontent-hub0 libcryptui0a libcupti7.5 libdata-alias-perl libdbus-cpp5 libdcmtk5 libdevmapper1.02.1:i386 libdirectfb-1.2-9 libdiscover2 libdns162 libdrm-amdgpu1:i386 libdrm-intel1:i386 libdrm-nouveau2:i386
  libdrm-radeon1:i386 libdrm2:i386 libebook-1.2-16 libedataserver-1.2-21 libedataserverui-1.2-1 libedit2:i386 libelf1:i386 libesd0 libespeak1 libevent-core-2.0-5 libevent-extra-2.0-5 libevent-openssl-2.0-5 libevent-pthreads-2.0-5 libfcitx-gclient0 libfreerdp-cache1.1
  libfreerdp-client1.1 libfreerdp-codec1.1 libfreerdp-common1.1.0 libfreerdp-core1.1 libfreerdp-crypto1.1 libfreerdp-gdi1.1 libfreerdp-locale1.1 libfreerdp-plugins-standard libfreerdp-primitives1.1 libfreerdp-rail1.1 libfreerdp-utils1.1 libfwupd1
  libgcc-5-dev-armhf-cross libgcr-3-common libghc-old-locale-dev libghc-old-locale-prof libghc-old-time-dev libghc-old-time-prof libgif7:i386 libgit2-24 libgl2ps0 libglapi-mesa:i386 libglvnd0:i386 libgmime-2.6-0 libgnome-desktop-3-12 libgoogle-glog0v5 libgps22
  libgranite2 libgweather-3-6 libhardware2 libhdf5-10 libhdf5-cpp-11 libhttp-parser2.1 libhud2 libhunspell-1.3-0 libhybris libical1a libicu55:i386 libidn11:i386 libidn11-dev libiphb0 libisccfg140 libiscsi2 libiso9660-8 libjasper-dev libjavascriptcoregtk-3.0-0
  libjavascriptcoregtk-4.0-dev libjpeg9 libk3b6 libk3b6-extracodecs libk3b7 libk3b7-extracodecs libkcddb4 libkcompactdisc4 libkf5activitiesexperimentalstats1 libkf5calendarcore5 libkf5cddb-data libkf5cddb5 libkf5gpgmepp-pthread5 libkf5gpgmepp5 libkf5identitymanagement5
  libkf5kdgantt2-5 libkf5kipi30.0.0 libkf5libkleo5 libkf5mime5 libkf5pimtextedit5 libkf5prison1 libkf5qgpgme5 libkwineffects7 libkwinglutils7 libkwinxrenderutils7 liblensfun-data liblensfun0 liblibertine1 liblink-grammar4 liblircclient0 liblivemedia50 libllvm3.6v5
  libllvm4.0 libllvm6.0:i386 liblouis9 liblouisutdml6 liblttng-ust-ctl2 liblttng-ust-ctl4 liblttng-ust0 liblwres141 libmedia1 libmono-c5-1.1-cil libmonoboehm-2.0-1 libmonoboehm-2.0-dev libmozjs-24-0v5 libnet-cpp2 libnfs8 liboce-foundation10 liboce-modeling10
  liboce-ocaf-lite10 liboce-ocaf10 liboce-visualization10 libode4 libokularcore7 libonline-accounts-client1 libopencv-gpu2.4v5 libopencv-legacy2.4v5 libopencv-ocl2.4v5 libopencv-photo2.4v5 libopencv-stitching2.4v5 libopencv-superres2.4v5 libopencv-ts2.4v5
  libopencv-videostab2.4v5 libopencv2.4-jni liborcus-0.10-0v5 libp11-kit-gnome-keyring libp11-kit-gnome-keyring:i386 libpackagekitqt5-0 libpciaccess0:i386 libpng12-0:i386 libpodofo0.9.3 libpoppler-qt4-4 libpoppler58 libportaudiocpp0 libprocess-cpp3 libprotobuf9v5
  libprotoc9v5 libpython3.5-dev libqbscore1 libqbsqtprofilesetup1 libqcustomplot1.3 libqmobipocket1 libqt5clucene5 libqt5contacts5 libqt5feedback5 libqt5organizer5 libqt5systeminfo5 libqtcurve-utils2 libquvi-scripts libquvi7 libraptor1 librhash0 librpm3 librpmbuild3
  librpmio3 librpmsign3 libsensors4:i386 libsidutils0 libsignon-extension1 libsignon-glib1 libsodium18 libsoup2.4-dev libsox2 libspice-client-gtk-3.0-4 libssl1.0.0:i386 libstdc++-5-dev-armhf-cross libthumbnailer-qt1.0 libtorrent-rasterbar8 libtrust-store2
  libtxc-dxtn-s2tc0 libtxc-dxtn-s2tc0:i386 libubuntu-app-launch2 libubuntu-download-manager-client1 libubuntu-download-manager-common1 libubuntu-location-service3 libudm-common1 libudm-priv-common1 libuninameslist0 libunity-action-qt1 libunity-api0 libunity-scopes1.0
  liburcu4 liburcu6 libva-drm1 libvamp-sdk2v5 libvirt-bin libvpx3:i386 libvte-common libvte9 libwebkit2gtk-4.0-dev libwebkitgtk-3.0-0 libwebpdemux1 libwebpmux1 libwebrtc-audio-processing-0 libwinpr-crt0.1 libwinpr-dsparse0.1 libwinpr-environment0.1 libwinpr-file0.1
  libwinpr-handle0.1 libwinpr-heap0.1 libwinpr-input0.1 libwinpr-interlocked0.1 libwinpr-library0.1 libwinpr-path0.1 libwinpr-pool0.1 libwinpr-registry0.1 libwinpr-rpc0.1 libwinpr-sspi0.1 libwinpr-synch0.1 libwinpr-sysinfo0.1 libwinpr-thread0.1 libwinpr-utils0.1
  libx11-xcb1:i386 libxapian-1.3-5 libxapian22v5 libxcb-dri2-0:i386 libxcb-dri3-0:i386 libxcb-glx0:i386 libxcb-present0:i386 libxcb-sync1:i386 libxen-4.6 libxfont1 libxfont1-dev libxfreerdp-client1.1 libxshmfence1:i386 libxt6:i386 libzita-alsa-pcmi0 libzita-resampler1
  libzmqpp3 linux-headers-4.4.0-186 linux-headers-4.4.0-186-generic linux-image-4.4.0-186-generic linux-libc-dev:i386 linux-modules-4.4.0-186-generic linux-modules-extra-4.4.0-186-generic linuxsampler-vst llvm-4.0 llvm-4.0-dev llvm-4.0-runtime lufsmeter-vst luftikus-vst
  lv2-dev mda-vst mod-sdk-lv2 moony.lv2 obxd-vst openjdk-8-doc oxefmsynth oxideqt-codecs-extra p11-kit-modules:i386 pitcheddelay-vst pizmidi-plugins prosper python-feedparser python-ndg-httpsclient python-utidylib python-yenc python3-apparmor-click python3-click-package
  python3-dbus.mainloop.qt python3-plainbox python3-pyqt4 python3.5-dev qml-module-qtfeedback qml-module-qttest qml-module-ubuntu-onlineaccounts-client qml-module-ubuntu-performancemetrics qml-module-ubuntu-thumbnailer0.1 qtdeclarative5-accounts-plugin
  qtdeclarative5-online-accounts-client0.1 qtdeclarative5-test-plugin qtdeclarative5-ubuntu-content1 qtdeclarative5-ubuntu-download-manager0.1 qtdeclarative5-ubuntu-thumbnailer0.1 qtdeclarative5-unity-action-plugin qtdeclarative5-unity-notifications-plugin rename
  rtirq-init rubberband-lv2 rubberband-vamp ruby2.3 seahorse-daemon sherlock.lv2 signon-plugin-password signon-ui signon-ui-service signon-ui-x11 signond sorcer suru-icon-theme tal-plugins-vst tcpd teragonaudio-plugins-vst thumbnailer-service ttf-alee ttf-wqy-microhei
  ubuntu-app-launch ubuntu-download-manager ubuntu-mobile-icons ubuntu-release-upgrader-qt unity-plugin-scopes unity-scope-gdrive url-dispatcher vamp-examples whysynth wine-gecko2.21:i386 wine-gecko2.21 wine-mono0.0.8 wine1.6-i386:i386 wolpertinger-vst wsynth-dssi
  x11proto-bigreqs-dev x11proto-xcmisc-dev x42-plugins xsynth-dssi yudit-common
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
  libc6-armhf-cross libc6-dev-armhf-cross ubuntu-app-launch
The following packages will be upgraded:
  libc6-armhf-cross libc6-dev-armhf-cross ubuntu-app-launch
3 upgraded, 0 newly installed, 0 to remove and 51 not upgraded.
19 not fully installed or removed.
Need to get 0 B/2,918 kB of archives.
After this operation, 111 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 965024 files and directories currently installed.)
Preparing to unpack .../libc6-dev-armhf-cross_2.27-3ubuntu1cross1.1_all.deb ...
Unpacking libc6-dev-armhf-cross (2.27-3ubuntu1cross1.1) over (2.23-0ubuntu3cross1) ...
dpkg: error processing archive /var/cache/apt/archives/libc6-dev-armhf-cross_2.27-3ubuntu1cross1.1_all.deb (--unpack):
 unable to open '/usr/arm-linux-gnueabihf/lib/Mcrt1.o.dpkg-new': No such file or directory
No apport report written because the error message indicates an issue on the local system
                                                                                         Preparing to unpack .../libc6-armhf-cross_2.27-3ubuntu1cross1.1_all.deb ...
Unpacking libc6-armhf-cross (2.27-3ubuntu1cross1.1) over (2.23-0ubuntu3cross1) ...
dpkg: error processing archive /var/cache/apt/archives/libc6-armhf-cross_2.27-3ubuntu1cross1.1_all.deb (--unpack):
 unable to open '/usr/arm-linux-gnueabihf/lib/ld-2.27.so.dpkg-new': No such file or directory
No apport report written because the error message indicates an issue on the local system
                                                                                         Preparing to unpack .../ubuntu-app-launch_0.12+17.04.20170404.2-0ubuntu6_amd64.deb ...
Traceback (most recent call last):
  File "/usr/bin/click", line 37, in <module>
    import click_package as click
ModuleNotFoundError: No module named 'click_package'
dpkg: warning: old ubuntu-app-launch package pre-removal script subprocess returned error exit status 1
dpkg: trying script from the new package instead ...
dpkg: error processing archive /var/cache/apt/archives/ubuntu-app-launch_0.12+17.04.20170404.2-0ubuntu6_amd64.deb (--unpack):
 there is no script in the new version of the package - giving up
Errors were encountered while processing:
 /var/cache/apt/archives/libc6-dev-armhf-cross_2.27-3ubuntu1cross1.1_all.deb
 /var/cache/apt/archives/libc6-armhf-cross_2.27-3ubuntu1cross1.1_all.deb
 /var/cache/apt/archives/ubuntu-app-launch_0.12+17.04.20170404.2-0ubuntu6_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

If I try to remove the packages causing dpkg errors (like libc6-dev-armhf-cross), apt tells me... that I can't because I have unmet dependencies... namely libc6-dev-armhf-cross;

adamthedog@adam-linux:~$ sudo apt purge libc6-dev-armhf-cross 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 libasan2-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libasan4-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libatomic1-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libc6-dev-armhf-armel-cross : Depends: libc6-dev-armhf-cross but it is not going to be installed
 libcilkrts5-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libgcc1-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libgomp1-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libstdc++-5-dev-armhf-cross : Depends: libc6-dev-armhf-cross (>= 2.13-0ubuntu6) but it is not going to be installed
 libstdc++-7-dev-armhf-cross : Depends: libc6-dev-armhf-cross (>= 2.13-0ubuntu6) but it is not going to be installed
 libstdc++6-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 libubsan0-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed
 ubuntu-app-launch : Depends: upstart (>= 1.13) but it is not installable
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

What do I do?

Answer 1

I think the key is in this line of the last error message you wrote:

libasan2-armhf-cross : Depends: libc6-armhf-cross (>= 2.27) but 2.23-0ubuntu3cross1 is to be installed

When it says 2.23-0ubuntu3cross1 is to be installed it means that the version of libc6-armhf-cross known by apt is 2.23-.... Therefore, if you apt install libc6-armhf-cross, you'll get 2.23-.... Unfortunately, that's insufficient because apt was in the middle of installing something else which requires (>= 2.27).

There are a few things that could cause this:

1. If you tried installing a *.deb directly from a newer version of ubuntu or from a PPA which doesn't support your version (suite). The deb may not have support for the dependencies provided in your version. In that case, try installing the version for your specific suite.
2. You may simple need to download the latest release-info from your repository so you know what the current versions of everything are. apt update to get it
3. You are in the middle of upgrading your suite, you may be able to resolve this with apt dist-upgrade. Judging by the number of autoremoves, I suspect this might be the case.
4. Pinning can break systems pretty badly. If you have anything in /etc/apt/preferences.d/ please add it to your question. This contains rules for things like prioritizing one version over another.

Either-way, editing your answer to include the output of cat /etc/apt/sources.list /etc/apt/sources.list.d/*.list and any information on whether you've changed that recently would be useful.

I find that when I do a suite upgrade, it's easiest to keep toggling through the following commands until everything works. As long as your sources and pinning are configured properly, this usually solves things:

apt update
apt upgrade
apt dist-upgrade
apt --fix-broken install