#18849 `pants package ::` can corrupt directory target output by leaving stale/deleted contents Issue created by huonw Describe the bug A packageable target can sometimes be a directory. For instance,

pex_binary(..., layout="packed")

(or

layout="loose"

). If someone has run

pants package ::

once to output this target, makes a change that removes files, and then reruns

pants package ::

, the removed files are left there. In theory, writing to

dist/

should exactly synchronise the contents of a target-that-outputs-directory (removing stale contents). This will need to be done at an appropriate level, e.g. for a packed pex

pants package path/to:target

, it'll output

dist/path.to/target.pex/...

, but it should only synchronise

dist/path.to/target.pex/

, not removing anything from

dist/

or

dist/path.to/

. This likely applies to other methods of writing to

dist/

, like

export-codegen

. Reproducer:

cd $(mktemp -d)
cat > pants.toml <<EOF
[GLOBAL]
pants_version = "2.15.0"
backend_packages = ["pants.backend.python"]

[anonymous-telemetry]
enabled = false
EOF

cat > BUILD <<EOF
python_sources(name="sources")
pex_binary(name="pex", layout="packed", dependencies=[":sources"])
EOF

touch a.py b.py

# initial export:
pants package :pex
tree dist

rm b.py
pants package :pex
# BUG: b.py is still in dist/pex.pex/
tree dist

# clear out and start again to validate the expected contents (no b.py)
rm -rf dist
pants package :pex
tree dist

Output: 1.

initial export

08:43:37.96 [INFO] Wrote dist/pex.pex
    dist
    └── pex.pex
        ├── PEX-INFO
        ├── __main__.py
        ├── __pex__
        │   └── __init__.py
        ├── a.py
        └── b.py
    
    2 directories, 5 files

2.

BUG: b.py is still in dist/pex.pex/

08:43:38.33 [WARN] Unmatched glob from //b.py:sources's `source` field: "b.py"
    
    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 not being able to see the file(s) even though they exist on disk. Refer to <https://www.pantsbuild.org/v2.15/docs/troubleshooting#pants-cannot-find-a-file-in-your-project>.
    08:43:38.33 [INFO] Wrote dist/pex.pex
    dist
    └── pex.pex
        ├── PEX-INFO
        ├── __main__.py
        ├── __pex__
        │   └── __init__.py
        ├── a.py
        └── b.py
    
    2 directories, 5 files

3.

clear out and start again ...

08:43:38.74 [INFO] Wrote dist/pex.pex
    dist
    └── pex.pex
        ├── PEX-INFO
        ├── __main__.py
        ├── __pex__
        │   └── __init__.py
        └── a.py
    
    2 directories, 4 files

Pants version 2.15.0 OS macOS Additional info Potentially vaguely related: #17758, #18809. pantsbuild/pants