--appimage-extract-and-run: mkdir_p error: Permission denied on FreeBSD

Trying to `--appimage-extract-and-run` a x86_64 __Linux__ AppImage on FreeBSD 12.1-RELEASE-p8 with the Linux compatibility layer:

```
user@FreeBSD$ /home/user/Downloads/Akira-26-x86_64.AppImage --appimage-extract-and-run
mkdir_p error: Permission denied
Failed to extract AppImage
```

but

```
user@FreeBSD$ /home/user/Downloads/Akira-26-x86_64.AppImage --appimage-extract
```

```
user@FreeBSD$ truss /home/user/Downloads/Akira-26-x86_64.AppImage --appimage-extract-and-run 2>&1 | grep tmp
linux_access("/tmp/appimage_extracted_11b387e8ae9d3b2f6c030e4cfa7e8cc2/",F_OK) ERR#-2 'No such file or directory'
linux_mkdir("/tmp",493) ERR#-13 'Permission denied'
```

Doing manually:

```
user@FreeBSD$ mkdir -p /tmp/appimage_extracted_11b387e8ae9d3b2f6c030e4cfa7e8cc2/
```

works though, so why are we failing then?