After further discussion, it appears that only mmcblkp1 (the SD-card) was detected by the installer - so was the only option for installation.
Begin: Loading essential drivers ... [ 7.554515] mmc0: Failed to initialize a non-removable card -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2106499 Title: Installation fails with 'OSError: [Errno 16] Device or resource busy: '/dev/mmcblk1p3'' To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/subiquity/+bug/2106499/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
