#20479 `pants_ignore`d files are still referenced by `pants tailor` with `--changed-since` Issue created by blimmer Describe the bug I have a

_scaffolding

directory that I use to generate new projects in my monorepo. Inside this directory, there are

BUILD

files, but they're templates, so

pants

should ignore them.

_scaffolding
├── _cdk-common
│   └── Makefile
├── ecs_task
│   ├── template.toml
│   └── {{project_name}}
│       ├── BUILD
│       ├── Makefile -> ../../_cdk-common/Makefile
│       ├── README.md
│       └── src
└── generic
    ├── template.toml
    └── {{project_name}}
        ├── BUILD
        ├── Makefile -> ../../_cdk-common/Makefile
        ├── README.md
        └── src

Previously,

[GLOBAL].pants_ignore.add=["/_scaffolding/"]

seemed to do the trick to ignore these files. However, starting with Pants 2.18, tailor is not ignoring these files as before:

> pants \
  --changed-since=origin/main \
  tailor --check
08:39:40.80 [INFO] Initializing scheduler...
08:39:43.07 [INFO] Scheduler initialized.
08:39:43.61 [ERROR] 1 Exception encountered:

Engine traceback:
  in `tailor` goal

IntrinsicError: Unmatched globs from `--changed-since`: ["_scaffolding/ecs_task/{{project_name}}/*", "_scaffolding/generic/{{project_name}}/*"]

Do the file(s) exist? If so, check if the file(s) are in your `.gitignore` or the global `pants_ignore` option, which may result in Pants being unable to see the file(s) even though they exist on disk. Refer to <https://www.pantsbuild.org/v2.19/docs/troubleshooting#pants-cannot-find-a-file-in-your-project>.

I've tried: •

[GLOBAL].build_ignore = ["_scaffolding/*"]

•

[tailor].ignore_paths = ["_scaffolding/*"]

But the error persists. Pants version 2.19.0 The issue seems to have been introduced in the 2.18.x series, as I never had a problem with this before 2.18.x. OS MacOS and Linux Additional info @tgolsson and I were discussing this in Slack. He was able to reproduce the issue, as well. Workaround From @tgolsson :

1. Add a DUMMY file next to your BUILD file

2. After your scaffolding ignore regex, explicitly override to include the dummy file

3. In your build ignore, only mention the BUILD file

pantsbuild/pants