Random losetup errors while building inside mock

[benzea]

I am trying to build a Fedora 26 live image inside mock. For this I am currently using "--old-chroot" option for mock as otherwise /dev/loop does not even exist.

(The -squashfs_args "-noD -noI -noF -noX -no-duplicates" was me trying to speed up mksquashfs, not that it worked.)

2017-08-10 16:15:46,260: Configuring installed system
2017-08-10 16:15:46,312: .
2017-08-10 16:15:46,313: Creating users
2017-08-10 16:15:46,327: .
2017-08-10 16:15:46,327: Configuring addons
2017-08-10 16:15:59,737: .
2017-08-10 16:15:59,738: Generating initramfs
2017-08-10 16:16:01,522: .
2017-08-10 16:16:01,522: Running post-installation scripts
2017-08-10 16:16:01,523: .
2017-08-10 16:16:01,523: Storing configuration files and kickstarts
2017-08-10 16:16:01,524: .
2017-08-10 16:16:34,460: Shutting down log processing
2017-08-10 16:16:35,316: Disk Image install successful
2017-08-10 16:16:35,316: working dir is /var/tmp/lmc-work-_eugkhmt
2017-08-10 16:31:10,101: Rebuilding initrds
2017-08-10 16:31:10,101: dracut args = ['--xz', '--add', 'livenet dmsquash-live convertfs pollcdrom qemu qemu-net', '--omit', 'plymouth', '--no-hostonly', '--debug', '--no-early-microcode']
2017-08-10 16:31:10,103: rebuilding boot/initramfs-4.11.11-300.fc26.x86_64.img
2017-08-10 16:31:52,932: Building boot.iso
2017-08-10 16:31:52,981: running x86.tmpl
2017-08-10 16:32:00,012: command output:
Traceback (most recent call last):
  File "/usr/sbin/mkefiboot", line 167, in <module>
    main()
  File "/usr/sbin/mkefiboot", line 160, in main
    mkefiboot(opt.bootdir, opt.outfile, opt.label)
  File "/usr/sbin/mkefiboot", line 33, in mkefiboot
    mkdosimg(None, outfile, label=label, graft={'EFI/BOOT':bootdir})
  File "/usr/lib/python3.6/site-packages/pylorax/imgutils.py", line 437, in mkdosimg
    mkfsargs=["-n", label], graft=graft)
  File "/usr/lib/python3.6/site-packages/pylorax/imgutils.py", line 417, in mkfsimage
    with LoopDev(outfile, size) as loopdev:
  File "/usr/lib/python3.6/site-packages/pylorax/imgutils.py", line 297, in __enter__
    self.loopdev = loop_attach(self.filename)
  File "/usr/lib/python3.6/site-packages/pylorax/imgutils.py", line 154, in loop_attach
    dev = runcmd_output(["losetup", "--find", "--show", outfile])
  File "/usr/lib/python3.6/site-packages/pylorax/executils.py", line 347, in runcmd_output
    return execWithCapture(cmd[0], cmd[1:], **kwargs)
  File "/usr/lib/python3.6/site-packages/pylorax/executils.py", line 249, in execWithCapture
    reset_handlers=reset_handlers, reset_lang=reset_lang)[1]
  File "/usr/lib/python3.6/site-packages/pylorax/executils.py", line 201, in _run_program
    raise subprocess.CalledProcessError(proc.returncode, argv, output)
subprocess.CalledProcessError: Command '['losetup', '--find', '--show', '/var/tmp/lmc-work-_eugkhmt/images/efiboot.img']' returned non-zero exit status 1.

2017-08-10 16:32:00,012: command returned failure (1)
2017-08-10 16:32:00,013: template command error in x86.tmpl:
2017-08-10 16:32:00,013:   runcmd mkefiboot --label=ANACONDA /var/tmp/lmc-work-_eugkhmt/EFI/BOOT /var/tmp/lmc-work-_eugkhmt/images/efiboot.img
2017-08-10 16:32:00,015:   subprocess.CalledProcessError: Command '['mkefiboot', '--label=ANACONDA', '/var/tmp/lmc-work-_eugkhmt/EFI/BOOT', '/var/tmp/lmc-work-_eugkhmt/images/efiboot.img']' returned non-zero exit status 1.
Traceback (most recent call last):
  File "/usr/sbin/livemedia-creator", line 1476, in <module>
    main()
  File "/usr/sbin/livemedia-creator", line 1413, in main
    result_dir = make_livecd(opts, mount_dir, work_dir)
  File "/usr/sbin/livemedia-creator", line 637, in make_livecd
    tb.build()
  File "/usr/lib/python3.6/site-packages/pylorax/treebuilder.py", line 311, in build
    self._runner.run(templatefile, kernels=self.kernels)
  File "/usr/lib/python3.6/site-packages/pylorax/ltmpl.py", line 220, in run
    self._run(commands)
  File "/usr/lib/python3.6/site-packages/pylorax/ltmpl.py", line 239, in _run
    f(*args)
  File "/usr/lib/python3.6/site-packages/pylorax/ltmpl.py", line 515, in runcmd
    stdout = runcmd_output(cmd)
  File "/usr/lib/python3.6/site-packages/pylorax/executils.py", line 347, in runcmd_output
    return execWithCapture(cmd[0], cmd[1:], **kwargs)
  File "/usr/lib/python3.6/site-packages/pylorax/executils.py", line 249, in execWithCapture
    reset_handlers=reset_handlers, reset_lang=reset_lang)[1]
  File "/usr/lib/python3.6/site-packages/pylorax/executils.py", line 201, in _run_program
    raise subprocess.CalledProcessError(proc.returncode, argv, output)
subprocess.CalledProcessError: Command '['mkefiboot', '--label=ANACONDA', '/var/tmp/lmc-work-_eugkhmt/EFI/BOOT', '/var/tmp/lmc-work-_eugkhmt/images/efiboot.img']' returned non-zero exit status 1.
Finish: chroot ['livemedia-creator --squashfs_args "-noD -noI -noF -noX -no-duplicates" --ks flat-hwtest-live.ks --no-virt --resultdir /var/lmc --project Fedora-HWTest --make-iso --kernel-args="crashkernel=256M" --volid Fedora-HWTest-26 --iso-only --iso-name Fedora-HWTest-26-x86_64.iso --releasever 26 --title Fedora-HWTest-live --macboot']
ERROR: Command failed: 
 # /bin/sh -c livemedia-creator --squashfs_args "-noD -noI -noF -noX -no-duplicates" --ks flat-hwtest-live.ks --no-virt --resultdir /var/lmc --project Fedora-HWTest --make-iso --kernel-args="crashkernel=256M" --volid Fedora-HWTest-26 --iso-only --iso-name Fedora-HWTest-26-x86_64.iso --releasever 26 --title Fedora-HWTest-live --macboot

[bcl]

Try adding this patch to mock and see if it works better for you: rpm-software-management/mock#107

[benzea]

OK, seems pretty good. I have done 3 builds in a row without an issue so far.

[bleve]

Noticed same error with epel7 mock. Patch fixed the issue here too.

[yuvalturg]

loop-control creates loop devices under /dev outside mock even if the request is from inside - just add a few loop devices before calling lmc if it's still an issue... something like:
seq 0 9 | xargs -I {} mknod /dev/loop{} b 7 {}

[bcl]

mock --old-chroot now creates the loop devices even if they aren't present on the host. Closing this.