Bug#889990: gnome-boxes: Unable to start VMs because CPU mode 'custom' for x86_64 kvm domain on x86_64 host is not supported

[Nick Quinn]

Package: gnome-boxes
Version: 3.27.90-1
Severity: important

Dear Maintainer,

gnome-boxes is unusable for me as every time I start a VM it throws this error.

I can create and run VMs with libvirt using virt-manager, but if I import those VMs into gnome-boxes, immediately the same error is thrown.

If I attempt to manually amend the gnome boxes config for the VM (boxes-unknown) to the correct CPU config, then as soon as gnome-boxes tries to start the VM again, it overwrites the change.


-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.14.0-3-amd64 (SMP w/16 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages gnome-boxes depends on:
ii  dconf-gsettings-backend [gsettings-backend]  0.26.1-3
ii  libarchive13                                 3.2.2-3.1
ii  libc6                                        2.26-4
ii  libcairo2                                    1.15.10-1
ii  libgdk-pixbuf2.0-0                           2.36.11-1
ii  libglib2.0-0                                 2.54.3-2
ii  libgovirt2                                   0.3.4-2
ii  libgtk-3-0                                   3.22.26-2
ii  libgtk-vnc-2.0-0                             0.7.1-1
ii  libgudev-1.0-0                               232-2
ii  libosinfo-1.0-0                              1.1.0-1
ii  libosinfo-bin                                1.1.0-1
ii  libpango-1.0-0                               1.40.14-1
ii  librest-0.7-0                                0.8.0-2
ii  libsecret-1-0                                0.18.5-6
ii  libsoup2.4-1                                 2.60.3-1
ii  libspice-client-glib-2.0-8                   0.34-1.1
ii  libspice-client-gtk-3.0-5                    0.34-1.1
ii  libtracker-sparql-2.0-0                      2.0.2-1
ii  libusb-1.0-0                                 2:1.0.21-2
ii  libvirt-daemon                               4.0.0-1
ii  libvirt-glib-1.0-0                           1.0.0-1
ii  libwebkit2gtk-4.0-37                         2.18.6-1
ii  libxml2                                      2.9.4+dfsg1-6.1
ii  mtools                                       4.0.18-2+b1
ii  tracker                                      2.0.2-1

Versions of packages gnome-boxes recommends:
ii  qemu-system-x86  1:2.11+dfsg-1

gnome-boxes suggests no packages.

-- no debconf information