adding support for a nix.fish script along side $HOME/.nix-profile/etc/profile.d/nix.sh

[cartazio]

hey all,
to complement the nix.sh script, because I use fish as my root shell,
i had to write a nix.fish

https://gist.github.com/cartazio/21523fb72db0227611ac is that file

and inline here too

#! /usr/local/bin/fish
if test  -n "$HOME" ;
    set -xg NIX_LINK "$HOME/.nix-profile"

    # Set the default profile.
    if not test -L "$NIX_LINK" ;
        echo "creating $NIX_LINK" >&2
        set -l _NIX_DEF_LINK /nix/var/nix/profiles/default
        /nix/store/cdybb3hbbxf6k84c165075y7vkv24vm2-coreutils-8.23/bin/ln -s "$_NIX_DEF_LINK" "$NIX_LINK"
    end

    set -xg PATH $NIX_LINK/bin $NIX_LINK/sbin $PATH

    # Subscribe the user to the Nixpkgs channel by default.
    if not test -e $HOME/.nix-channels ;
        echo "https://nixos.org/channels/nixpkgs-unstable nixpkgs" > $HOME/.nix-channels
    end

    # Append ~/.nix-defexpr/channels/nixpkgs to $NIX_PATH so that
    # <nixpkgs> paths work when the user has fetched the Nixpkgs
    # channel.
    # set -xg  NIX_PATH ${NIX_PATH:+$NIX_PATH:}nixpkgs=$HOME/.nix-defexpr/channels/nixpkgs
    set -xg  NIX_PATH $NIX_PATH $HOME/.nix-defexpr/channels/nixpkgs

    # Set $SSL_CERT_FILE so that Nixpkgs applications like curl work.
    if test  -e /etc/ssl/certs/ca-bundle.crt ;  # Fedora, NixOS
        set -xg SSL_CERT_FILE /etc/ssl/certs/ca-bundle.crt ;
    else if test -e /etc/ssl/certs/ca-certificates.crt ;  # Ubuntu, Debian
        set -xg SSL_CERT_FILE /etc/ssl/certs/ca-certificates.crt
    else if test -e "$NIX_LINK/etc/ca-bundle.crt" ;  # fall back to Nix profile
        set -xg SSL_CERT_FILE "$NIX_LINK/etc/ca-bundle.crt"
    end
end

How would I go about upstreaming this and (future) fish scripting support?
I understand some of this stuff is generated from various templates?

thanks!

[cartazio]

mind you, i'm still debugging/tweaking this to work right : )

[wmertens]

I'm thinking it would be better to split the script in a setup part and an
environment loading part, and have the setup part be a bash script that
gets called.

It would also be nice if the environment loading part just read a
cross-shell file so the shell environment is only defined in one place.

See also #452

On Sun Jan 11 2015 at 3:16:18 AM Carter Tazio Schonwald <
notifications@github.com> wrote:

mind you, i'm still debugging/tweaking this to work right : )

—
Reply to this email directly or view it on GitHub
#440 (comment).

[elasticdog]

I can't yet vouch for the script itself, but I'm a fish shell user as well and would love to have an officially supported version of the environment setup script.

[cspickert]

I wrote a bash script that sources the existing nix.sh script and dumps the environment setup as a sequence of fish commands. It would need to be modified if the original script changed, but it's enough to get things up and running.

#!/usr/bin/env bash

# Usage from fish: "eval (./nix_fish_env) 2>/dev/null"

# Abort if nix isn't installed
if ! [ -f ~/.nix-profile/etc/profile.d/nix.sh ]; then
    exit
fi

# Unset variables that will be loaded from nix init
unset PATH
unset SSL_CERT_FILE

# Load environment from nix init
source ~/.nix-profile/etc/profile.d/nix.sh

# Remove trailing `:` from PATH
PATH="${PATH%:}"

# Read PATH and NIX_PATH into arrays
IFS=: read -a PATH_ARRAY <<< "$PATH"
IFS=: read -a NIX_PATH_ARRAY <<< "$NIX_PATH"

# Echo fish commands to export environment variables
echo set -x PATH ${PATH_ARRAY[@]} \$PATH \;
echo set -x NIX_PATH ${NIX_PATH_ARRAY[@]} \;

if [ -f "$SSL_CERT_FILE" ]; then
    echo set -x SSL_CERT_FILE \'$SSL_CERT_FILE\' \;
fi

[wmertens]

So what's the next action on this? I presume your problem is solved, but
other fish users might want this. Should this be distributed alongside Nix?

On Fri, Apr 24, 2015 at 11:45 PM Cameron Spickert notifications@github.com
wrote:

I wrote a bash script
https://github.com/cspickert/fish/blob/master/misc/nix_fish_env.sh that
sources the existing nix.sh script and dumps the results as a sequence of
fish commands. It would need to be modified if the original script changed,
but it's enough to get things up and running.

—
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#440 (comment).

[jc00ke]

I would like to see this distributed by default.

[ryanartecona]

I don't know if anything's changed here, but I just ran into this. I'm looking to try out Nix in OS X, and I also use fish as my system shell. Is there anything preventing this fish profile script from being added?

[rened]

+1, would love to have this!

[edolstra]

Well, merging this would create a bit of a maintainability problem, since any future change to the bash profile script would have to be propagated to the fish script, and I don't know fish...

[Globegitter]

@edolstra just running into this as well and would love to see fish support.

I can see the issue with maintainability but most of fish syntax is quite easy to translate from bash, especially if you already have an example as above. (e.g. you have set -x instead of export, if end etc.) Creating a nix.fish from the original nix.sh took me about half an hour with barely any fish knowledge.

But you could also add it with the caveat that it is not fully tested and if any change breaks the existing fish script I am sure a fish user would step up to fix it.

[edolstra]

Okay, if somebody wants to make a PR, I'll merge it.

[rasendubi]

Any update on this? I can make a PR if it wasn't done yet and still needed.

[donut]

Just FYI, @cspickert's script still works. Maybe something like that would be easier to maintain as compared to completely duplicating everything in fish.

[domenkozar]

Doesn't #626 fix this?

[rasendubi]

Yeah, it does.

However, there was an idea to auto-generate nix.fish from the run of nix.sh. Not sure what way is better.