On Thu, Jun 22, 2023 at 3:56 PM David C Black [off-list ref] wrote:

Sitting at the rood of my working directory I attempted to add a file to the git repository with:

quoted

git add extern/bin/build

The repository had the following .gitignore file contents:

quoted

/extern/
!/extern/bin/
!/extern/ABOUT.md

I received an error message:

quoted

The following paths are ignored by one of your .gitignore files:
extern
hint: Use -f if you really want to add them.

By negating entries in the /extern/bin/ directory, I did not expect an error
message. Of course adding -f made it work, but I think it does not match the
described behavior for this tool.

This appears to be working as documented. From the gitginore(5) man page:

    An optional prefix "!" which negates the pattern; any matching
    file excluded by a previous pattern will become included again. It
    is not possible to re-include a file if a parent directory of that
    file is excluded.

In your .gitignore file, /extern/ is ignored, which means that the
subsequent "!/extern/.../" lines are ineffectual. So, as far as Git is
concerned, /extern/bin/build is indeed ignored, thus its refusal
without --force.