How to: dependency chickenbits
prevent loading an optional dependency  , for example if:

* you have an incompatible version installed and it causes problems
* you just don't want copyparty to use it, maybe to save ram

set any of the following environment variables to disable its associated optional feature,

| env-var              | what it does |
| -------------------- | ------------ |
| `PRTY_NO_ARGON2`     | disable argon2-cffi password hashing |
| `PRTY_NO_CFSSL`      | never attempt to generate self-signed certificates using [cfssl](https://github.com/cloudflare/cfssl) |
| `PRTY_NO_FFMPEG`     | **audio transcoding** goes byebye, **thumbnailing** must be handled by Pillow/libvips |
| `PRTY_NO_FFPROBE`    | **audio transcoding** goes byebye, **thumbnailing** must be handled by Pillow/libvips, **metadata-scanning** must be handled by mutagen |
| `PRTY_NO_MAGIC`      | do not use [magic](https://pypi.org/project/python-magic/) for filetype detection |
| `PRTY_NO_MUTAGEN`    | do not use [mutagen](https://pypi.org/project/mutagen/) for reading metadata from media files; will fallback to ffprobe |
| `PRTY_NO_PARAMIKO`   | disable sftp server ([paramiko](https://www.paramiko.org/)-based) |
| `PRTY_NO_PARTFTPY`   | disable tftp server ([partftpy](https://github.com/9001/partftpy)-based) |
| `PRTY_NO_PIL`        | disable all [Pillow](https://pypi.org/project/pillow/)-based thumbnail support; will fallback to libvips or ffmpeg |
| `PRTY_NO_PILF`       | disable Pillow `ImageFont` text rendering, used for folder thumbnails |
| `PRTY_NO_PIL_AVIF`   | disable Pillow avif support (internal and/or [plugin](https://pypi.org/project/pillow-avif-plugin/)) |
| `PRTY_NO_PIL_HEIF`   | disable 3rd-party Pillow plugin for [HEIF support](https://pypi.org/project/pillow-heif/) |
| `PRTY_NO_PIL_WEBP`   | disable use of native webp support in Pillow |
| `PRTY_NO_PSUTIL`     | do not use [psutil](https://pypi.org/project/psutil/) for reaping stuck hooks and plugins on Windows |
| `PRTY_NO_PYFTPD`     | disable ftp(s) server ([pyftpdlib](https://pypi.org/project/pyftpdlib/)-based) |
| `PRTY_NO_RAW`        | disable all [rawpy](https://pypi.org/project/rawpy/)-based thumbnail support for RAW images |
| `PRTY_NO_VIPS`       | disable all [libvips](https://pypi.org/project/pyvips/)-based thumbnail support; will fallback to Pillow or ffmpeg |

example: `PRTY_NO_PIL=1 python3 copyparty-sfx.py`

* `PRTY_NO_PIL` saves ram
* `PRTY_NO_VIPS` saves ram and startup time
* python2.7 on windows: `PRTY_NO_FFMPEG` + `PRTY_NO_FFPROBE` saves startup time