Package: qemu-system-x86 Version: 1:3.1+dfsg-2+b1 Virtual FAT disk images no longer work:
$ qemu-system-x86_64 -hda fat:$(mktemp -d) WARNING: Image format was not specified for 'json:{"fat-type": 0, "dir": "/tmp/tmp.n7Ee7StjCL", "driver": "vvfat", "floppy": false, "rw": false}' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'raw' format explicitly to remove the restrictions. qemu-system-x86_64: Initialization of device ide-hd failed: Block node is read-only -- System Information: Architecture: i386 Versions of packages qemu-system-x86 depends on: ii libaio1 0.3.111-1 ii libasound2 1.1.7-2 ii libbluetooth3 5.50-1 ii libbrlapi0.6 5.6-8+b1 ii libc6 2.28-4 ii libcacard0 1:2.6.1-1 ii libcapstone3 3.0.5-3 ii libepoxy0 1.5.3-0.1 ii libfdt1 1.4.7-3 ii libgbm1 18.2.8-2 ii libgcc1 1:8.2.0-14 ii libglib2.0-0 2.58.2-3 ii libgnutls30 3.6.5-2 ii libjpeg62-turbo 1:1.5.2-2+b1 ii libncursesw6 6.1+20181013-1 ii libnettle6 3.4.1~rc1-1 ii libnuma1 2.0.12-1 ii libpixman-1-0 0.36.0-1 ii libpng16-16 1.6.36-2 ii libsasl2-2 2.1.27~rc8-1 ii libseccomp2 2.3.3-3 ii libspice-server1 0.14.0-1.2 ii libtinfo6 6.1+20181013-1 ii libusb-1.0-0 2:1.0.22-2 ii libusbredirparser1 0.8.0-1 ii libvdeplug2 2.3.2+r586-2.1 ii libvirglrenderer0 0.7.0-2 ii libxendevicemodel1 4.11.1~pre.20180911.5acdd26fdc+dfsg-5 ii libxenevtchn1 4.11.1~pre.20180911.5acdd26fdc+dfsg-5 ii libxenforeignmemory1 4.11.1~pre.20180911.5acdd26fdc+dfsg-5 ii libxengnttab1 4.11.1~pre.20180911.5acdd26fdc+dfsg-5 ii libxenmisc4.11 4.11.1~pre.20180911.5acdd26fdc+dfsg-5 ii libxenstore3.0 4.11.1~pre.20180911.5acdd26fdc+dfsg-5 ii libxentoolcore1 4.11.1~pre.20180911.5acdd26fdc+dfsg-5 ii zlib1g 1:1.2.11.dfsg-1 ii qemu-system-common 1:3.1+dfsg-2+b1 ii qemu-system-data 1:3.1+dfsg-2 ii seabios 1.12.0-1 ii ipxe-qemu 1.0.0+git-20161027.b991c67-1 -- Jakub Wilk