RESOLVED: migrated installation fails to serve css

RESOLVED:

I'm guessing that edits to: /admin/appearance/settings/my_custom_theme, generate a file called: styles/css/generated/custom-css.css. I had imagined that this might be the case, and so used that path to make a small change to my custom css rules in my uat environment. But that failed to change the outcome. After resolving this issue, I checked on the uat installation and failed to find the expected generated file. I have no idea why that may be.

This provided some clues about the issue.

jenkins@efc9c26-01634:~/sites/ijan_crm/web/themes/custom/ijan$ git status 
On branch master
Your branch is up to date with 'origin/master'.

Untracked files:
  (use "git add <file>..." to include in what will be committed)
        styles/css/generated/custom-css.css

I took these steps to resolve the issue:

• ssh to my dev installation
• cd to custom theme
• used git status to inspect for changes
• migrated content from styles/css/generated/custom-css.css to styles/css/custom.css
• use git -m'commit message' styles/css/custom.css; git tag ; git push origin master --tags to push these changes to my remote repo
• ssh to my uat installation
• cd to custom theme
• git pull origin master --tags
• drush cr
• inspect results to find that my custom css is now being served

Have created pull request for atdocs project, here:
https://github.com/jmburnz/atdocs/pull/1

I have submitted a pull request on the atdocs project to document what I learned on this issue:
https://github.com/jmburnz/atdocs/pull/1