Stop showing BSD-specific installation messages on Linux!

[groggily]

For example:

firefox~single~std installation messages  ---------------------------------
## Missing features

Some features found on Windows, macOS and Linux are not implemented:

- Encrypted Media Extensions (requires Widevine CDM binary)
- Process sandboxing (requires Capsicum backend)
- Reduced memory usage (requires mozjemalloc)
- Crash Reporter (requires Google Breakpad and reproducible builds)
- WebVR (requires open source runtime)
- TCP fast open
- `about:networking#networkid` (requires link state notification)

## Audio backend

Currently used audio backend can be inspected on `about:support` page.
Supported backends and default probing order is as follows:
- `pulse-rust` if `pulseaudio` package is installed (PULSEAUDIO option)
- `jack` if `jackit` package is installed (JACK option)
- `sndio` if `sndio` package is installed (SNDIO option)
- `alsa` if `alsa-lib` package is installed (ALSA option)
- `oss` (always available)
To force a specific backend open `about:config` page and create
`media.cubeb.backend` preference.

Microphone selection only works in `oss`, `pulse-rust` backends.
Other backends are limited to `default` which is usually `/dev/dsp`,
so use virtual_oss to reroute microphones from non-default devices.

## Gamepad API

Requires evdev(4) joystick support. On FreeBSD 13 and later enable hgame(4)
while older versions can use sysutils/iichid or multimedia/webcamd.

## smb:// issues
Network group, machine, and share browsing does not work correctly.

## sftp://
Only sftp access using public key authentication works. To easily
setup public key authentication to `remote_host`:

    $ ssh-keygen
    $ cat ~/.ssh/id_rsa.pub | ssh remote_host "cat >> .ssh/authorized_keys"

The SSH server on `remote_host` must allow pub key authentication.

[jrmarino]

somebody will have to modify the port to make certain messages operating-system specific.

[jrmarino]

to be fair, I don't know how much of that message is false with regard to linux.
I'd wager most of it is relevant.

[groggily]

Your Firefox installs sndio even on Linux. I have the impression that you just took the options from BSD and build them as is on Linux.

[groggily]

I have no idea why but your Firefox also drags SDL2 as one of the dependencies.

[jrmarino]

Your Firefox installs sndio even on Linux. I have the impression that you just took the options from BSD and build them as is on Linux.

There are 2 reasons for that.

1. it builds on linux. The less differences between platforms the better
2. Much linux-specific audio support is missing (e.g. pulseaudio) So ravenports is trying to much up for it with other options.

[jrmarino]

I have no idea why but your Firefox also drags SDL2 as one of the dependencies.

you need to realize that firefox is many many years old (like 7?) and has no maintainer.
I don't know if SDL2 is required or not, but it might have been say 6 years ago.
when there is no dedicated maintainer, the rest of us just try to keep the package building.
Do you want the job?

[jrmarino]

and for the record, there's no DIRECT dependency on SDL2 according to the catalog. That means a dependency is pulling it in.