Created attachment 1286861 [details]
File: backtrace

Created attachment 1286862 [details]
File: cgroup

Created attachment 1286863 [details]
File: cpuinfo

Created attachment 1286864 [details]
File: environ

Created attachment 1286865 [details]
File: mountinfo

Created attachment 1286866 [details]
File: namespaces

Created attachment 1286867 [details]
File: open_fds

plasma-discover-5.10.2-1.fc26.x86_64.rpm  not crashingon on exit,but
when install some apps broke appstream cache,only when russian-fedora-repo-nonfree/free enabled(appstreamcli refresh fix this).

sorry other bug

It seems I have just hit this bug as well, in Fedora 26. 

I have tried to build an rpm in mock from source rpm, and it has crashed. Unfortunately, I haven't seen the exact mock error, but I have found in journactl:

Sep 15 21:34:36 xps python3[7224]: detected unhandled Python exception in '/usr/libexec/mock/mock'

When I try to re-run the build again it ends up with an error:

INFO: mock.py version 1.4.3 starting (python version = 3.6.2)...
Start: init plugins
INFO: selinux disabled
Finish: init plugins
Start: run
INFO: Start(SRPMS/python-ludolph-weather-1.0-1.fc26.src.rpm)  Config(fedora-26-x86_64)
Start: clean chroot
ERROR: Exception(SRPMS/python-ludolph-weather-1.0-1.fc26.src.rpm) Config(fedora-26-x86_64) 0 minutes 2 seconds
INFO: Results and/or logs in: /var/lib/mock/fedora-26-x86_64/result
Traceback (most recent call last):
  File "/usr/libexec/mock/mock", line 933, in <module>
    main()
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/libexec/mock/mock", line 736, in main
    run_command(options, args, config_opts, commands, buildroot, state)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/libexec/mock/mock", line 820, in run_command
    do_rebuild(config_opts, commands, buildroot, args)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/libexec/mock/mock", line 527, in do_rebuild
    post=post_build, clean=clean)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/libexec/mock/mock", line 470, in rebuild_generic
    commands.clean()
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.6/site-packages/mockbuild/backend.py", line 78, in clean
    self.buildroot.delete()
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.6/site-packages/mockbuild/buildroot.py", line 609, in delete
    util.rmtree(self.basedir, selinux=self.selinux)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.6/site-packages/mockbuild/util.py", line 151, in rmtree
    rmtree(fullname, selinux=selinux, exclude=exclude)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.6/site-packages/mockbuild/util.py", line 151, in rmtree
    rmtree(fullname, selinux=selinux, exclude=exclude)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.6/site-packages/mockbuild/util.py", line 151, in rmtree
    rmtree(fullname, selinux=selinux, exclude=exclude)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.6/site-packages/mockbuild/util.py", line 151, in rmtree
    rmtree(fullname, selinux=selinux, exclude=exclude)
  File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.6/site-packages/mockbuild/util.py", line 160, in rmtree
    os.rmdir(path)
OSError: [Errno 16] Device or resource busy: '/var/lib/mock/fedora-26-x86_64/root/var/cache/dnf'

This message is a reminder that Fedora 26 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 26. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as EOL if it remains open with a Fedora  'version'
of '26'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version'
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not
able to fix it before Fedora 26 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
of Fedora, you are encouraged  change the 'version' to a later Fedora
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's
lifetime, sometimes those efforts are overtaken by events. Often a
more recent Fedora release includes newer upstream software that fixes
bugs or makes them obsolete.

Fedora 26 changed to end-of-life (EOL) status on 2018-05-29. Fedora 26
is no longer maintained, which means that it will not receive any
further security or bug fix updates. As a result we are closing this bug.

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