This will create a FHS environment with many packages [expected to exist](https://github.com/AppImage/pkg2appimage/blob/master/excludelist) for the AppImage to work.
`wrapType2` expects an argument with the `src` attribute, and either a `name` attribute or `pname` and `version` attributes.
It will eventually call into [`buildFHSEnv`](#sec-fhs-environments), and any extra attributes in the argument to `wrapType2` will be passed through to it.
This means that you can pass the `extraInstallCommands` attribute, for example, and it will have the same effect as described in [`buildFHSEnv`](#sec-fhs-environments).
In the past, `appimageTools` provided both `wrapType1` and `wrapType2`, to be used depending on the type of AppImage that was being wrapped.
However, [those were unified early 2020](https://github.com/NixOS/nixpkgs/pull/81833), meaning that both `wrapType1` and `wrapType2` have the same behaviour now.
The argument passed to `wrapType2` can also contain an `extraPkgs` attribute, which allows you to include additional packages inside the FHS environment your AppImage is going to run in.
`extraPkgs` must be a function that returns a list of packages.
There are a few ways to learn which dependencies an application needs:
Use `extract` if you need to extract the contents of an AppImage.
This is usually used in Nixpkgs to install extra files in addition to [wrapping](#ssec-pkgs-appimageTools-wrapping) the AppImage.
`extract` expects an argument with the `src` attribute, and either a `name` attribute or `pname` and `version` attributes.
::: {.note}
In the past, `appimageTools` provided both `extractType1` and `extractType2`, to be used depending on the type of AppImage that was being extracted.
However, [those were unified early 2020](https://github.com/NixOS/nixpkgs/pull/81572), meaning that both `extractType1` and `extractType2` have the same behaviour as `extract` now.
:::
:::{.example #ex-extracting-appimage}
# Extracting an AppImage to install extra files
This example was adapted from a real package in Nixpkgs to show how `extract` is usually used in combination with `wrapType2`.
Note how `appimageContents` is used in `extraInstallCommands` to install additional files that were extracted from the AppImage.
The argument passed to `extract` can also contain a `postExtract` attribute, which allows you to execute additional commands after the files are extracted from the AppImage.
`postExtract` must be a string with commands to run.
