"PathFilter" can raise exception when executing "os.path.realpath()"

[Rodolfo Alonso]

"PathFilter" can raise exception when executing "os.path.realpath()". As seen in the CI log [1], "os.path.realpath()" calls "os.getcwd()". This method can return the reported exception if the [2] current directory has been deleted by other process. We should catch and unset this exception.

Log snippet: http://paste.openstack.org/show/789807/

Log: [1] https://164b3e6c67f8dffddea7-f89a5ef8d1bd221399a14347eddacf71.ssl.cf2.rackcdn.com/701733/41/check/neutron-functional/a3fabf6/testr_results.html

[2] https://stackoverflow.com/questions/3210902/python-why-does-os-getcwd-sometimes-crash-with-oserror

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/708936

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/708936
Committed: https://git.openstack.org/cgit/openstack/oslo.rootwrap/commit/?id=23a534b9f5f5aad2a95349f809e05cb9b6429f3c
Submitter: Zuul
Branch: master

commit 23a534b9f5f5aad2a95349f809e05cb9b6429f3c
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Fri Feb 21 15:28:23 2020 +0000

    Implement "realpath" to retrieve the real absolute path

    This function will call "os.path.realpth" and this in turn could call
    "os.getcwd". If the current path has been deleted by other application,
    this method will raise FileNotFoundError exception. This new function
    catches and unsets this exception, returning an empty string.

    Change-Id: If70411d8d189de4a020e528cd54412a5678cfab9
    Closes-Bug: #1864090

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/oslo.rootwrap 6.0.1 release.