just spent quite a bit of time debugging this, here's a minimal example:

```bash
# rm -rf a (if you want to reset)
cd /tmp
mkdir -p a/b
echo 'import os; os.chdir("..")' > a/b/c.py
cd a/b
python3 -m cProfile -o log.pstats c.py
ls -al
ls -al ..
```

example output:

```console
$ cd /tmp
$ mkdir -p a/b
$ echo 'import os; os.chdir("..")' > a/b/c.py
$ cd a/b
$ python3 -m cProfile -o log.pstats c.py
$ ls -al
total 12
drwxr-xr-x 2 asottile asottile 4096 May  3 20:35 .
drwxr-xr-x 3 asottile asottile 4096 May  3 20:35 ..
-rw-r--r-- 1 asottile asottile   26 May  3 20:35 c.py
$ ls -al ..
total 16
drwxr-xr-x  3 asottile asottile 4096 May  3 20:35 .
drwxrwxrwt 28 root     root     4096 May  3 20:35 ..
drwxr-xr-x  2 asottile asottile 4096 May  3 20:35 b
-rw-r--r--  1 asottile asottile  395 May  3 20:35 log.pstats
```

happy to work on a patch if this seems like a good idea to fix