build avoidance fails if reference build is read only

[Scott Little]

Brief Description
-----------------
A centos build using build avoidance will fail if the
upstream reference build is read only. The read only
is replicated in the user's build environment, and any
packages that need to be updates (since the reference
build) will fail with reason 'permission denied'

A read only reference build is rare, but can occur to
preserve important reference builds, such as a release build
or the last build prior tothe introduction of a major feature.

Severity
--------
Major

Steps to Reproduce
------------------
Write down the steps to reproduce the issue

Expected Behavior
------------------
Write down what was expected after taking the steps written above

Actual Behavior
----------------
Check out a released branch
build-pkg --build-avoidance

Reproducibility
---------------
100% if reference build is read only.

System Configuration
--------------------
N/A

Branch/Pull Time/Commit
-----------------------
Day one

Last Pass
---------
Never

Timestamp/Logs
--------------
N/A

Test Activity
-------------
Build

Workaround
----------
sudo chmod ug+w $MY_WORKSPACE

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/root/+/824990

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/root/+/824990
Committed: https://opendev.org/starlingx/root/commit/f3ba3ca0f1b93482047f6d56d33314cbb4fcdf15
Submitter: "Zuul (22348)"
Branch: master

commit f3ba3ca0f1b93482047f6d56d33314cbb4fcdf15
Author: Scott Little <email address hidden>
Date: Fri Jan 14 11:32:43 2022 -0500

    build-avoidance: ensure we can write to a copied build environment.

    A centos build using build avoidance will fail if the
    upstream reference build is read only. The read only
    is replicated in the user's build environment, and any
    packages that need to be updates (since the reference
    build) will fail with reason 'permission denied'

    A read only reference build is rare, but can occur to
    preserve important reference builds, such as a release build
    or the last build prior tothe introduction of a major feature.

    Solution is to add a chmod to ensure writability of copied content.

    Closes-Bug: 1958156
    Change-Id: Id7c4d9b90fe4b44cc8b1b351767a5dd74dc30e9a
    Signed-off-by: Scott Little <email address hidden>