* Aleksei Kovura (<email address hidden>) wrote:
> Ok, so I cloned from github and am bisecting like this (it's been a while, correct me if I'm wrong):
> $ git bisect start
> $ git bisect bad 1ab5eb4efb91a3d4569b0df6e824cc08ab4bd8ec # 2.10.0 stable commit
> $ git bisect good 359c41abe32638adad503e386969fa428cecff52 # 2.9.0 stable commit
> Bisecting: 1426 revisions left to test after this (roughly 11 steps)
> [269c20b2bbd2aa8531e0cdc741fb166f290d7a2b] tests/qdict: check more get_try_int() cases
> $ mkdir -p bin/269c20b2bbd2aa8531e0cdc741fb166f290d7a2b
> $ cd bin/269c20b2bbd2aa8531e0cdc741fb166f290d7a2b
> $ ../../configure --target-list=x86_64-softmmu --python=/usr/bin/python2 --enable-debug
> 
> Compilation fails with this (full log here
> https://pastebin.com/aUYyE6Bb):
> 
>   CC      block/block-backend.o
> /media/usb465gb_232gb_NTFS/compile/qemu/block/blkdebug.c: In function ‘blkdebug_refresh_filename’:
> /media/usb465gb_232gb_NTFS/compile/qemu/block/blkdebug.c:843:31: error: ‘%s’ directive output may be truncated writing up to 4095 bytes into a region of size 4086 [-Werror=format-truncation=]
>                   "blkdebug:%s:%s", s->config_file ?: "",
>                                ^~
> /media/usb465gb_232gb_NTFS/compile/qemu/block/blkdebug.c:842:9: note: ‘snprintf’ output 11 or more bytes (assuming 4106) into a destination of size 4096
>          snprintf(bs->exact_filename, sizeof(bs->exact_filename),
>          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>                   "blkdebug:%s:%s", s->config_file ?: "",
>                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>                   bs->file->bs->exact_filename);
>                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> cc1: all warnings being treated as errors
> make: *** [/media/usb465gb_232gb_NTFS/compile/qemu/rules.mak:66: block/blkdebug.o] Error 1
> make: *** Waiting for unfinished jobs....
> /media/usb465gb_232gb_NTFS/compile/qemu/block/blkverify.c: In function ‘blkverify_refresh_filename’:
> /media/usb465gb_232gb_NTFS/compile/qemu/block/blkverify.c:305:29: error: ‘%s’ directive output may be truncated writing up to 4095 bytes into a region of size 4086 [-Werror=format-truncation=]
>                   "blkverify:%s:%s",
>                              ^~
> /media/usb465gb_232gb_NTFS/compile/qemu/block/blkverify.c:304:9: note: ‘snprintf’ output between 12 and 8202 bytes into a destination of size 4096
>          snprintf(bs->exact_filename, sizeof(bs->exact_filename),
>          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>                   "blkverify:%s:%s",
>                   ~~~~~~~~~~~~~~~~~~
>                   bs->file->bs->exact_filename,
>                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>                   s->test_file->bs->exact_filename);
>                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> cc1: all warnings being treated as errors
> make: *** [/media/usb465gb_232gb_NTFS/compile/qemu/rules.mak:66: block/blkverify.o] Error 1
> 
> Did I hit a commit with a broken build or something? What to do next?

It's just the newer compiler is more fussy than the old one so when you
bisect you're not getting fixes for newer compilers.   You can pass
flags to the configure to use extra clfgas to turn this particular
warning off.

Dave

> -- 
> You received this bug notification because you are a member of qemu-
> devel-ml, which is subscribed to QEMU.
> https://bugs.launchpad.net/bugs/1715700
> 
> Title:
>   Windows 7 guest won't boot on qemu 2.10 (works on 2.9)
> 
> Status in QEMU:
>   New
> 
> Bug description:
>   Qemu version: 2.10 stable.
>   Guest: Windows 7 SP1 x64, virtio drivers are already installed in the guest.
>   Command line:
>   qemu-system-x86_64 \
>       -nodefaults \
>       -nodefconfig \
>       -machine type=q35,accel=kvm \
>       -enable-kvm \
>       -cpu host \
>       -m 2048 \
>       -vga virtio \
>       -boot menu=on \
>       -smbios file=/path/dmidecode_BIOS.bin \
>       -acpitable file=/path/acpi_slic.bin \
>       -bios /path/OVMF_CODE.fd \
>       -net none \
>       -drive if=virtio,media=disk,file=/media/win7.qcow2 \
>       -device pcie-root-port \
>       -device ich9-usb-ehci1 \
>       -device ich9-usb-uhci1 \
>       -device ich9-usb-uhci2 \
>       -device ich9-usb-uhci3
> 
>   Windows hangs at boot with waving flag screen (flag doesn't freeze,
>   keeps waving indefinitely). Same command line boots fine with Qemu
>   2.9. I tried changing machine type to pc-q35-2.9 - same result.
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/1715700/+subscriptions
> 
--
Dr. David Alan Gilbert / <email address hidden> / Manchester, UK