I'm trying to use nix-shell with a shell.nix file to get a clean development environment but I don't know how to change the location of the temporary build directories.
The buildInputs packages are built in /tmp but this path doesn't have enough space and I get an error: [Errno 28] No space left on device during the build.
I tried running nix-shell with a modified TMPDIR environment variable but it only affects the location of the nix-shell temporary files. The nix-build files are still put in /tmp.
I also tried to export a new value for TMPDIR in the shellHook but it doesn't work.
How can I change the TMPDIR of nix-build when it's started by nix-shell?
Here's my shell.nix:
let
pkgs = import <nixpkgs> {};
in
pkgs.mkShell {
name = "something";
buildInputs = with pkgs; [
python38
python38Packages.pytorchWithCuda
];
shellHook = ''
'';
}
I got the answer on the NixOS forum:
If this is a mutli-user install, you need to modify the Nix daemon’s TMPDIR.
To do that on my system I created a /etc/systemd/system/nix-daemon.service.d/override.conf with:
[Service]
Environment=TMPDIR=/var/tmp/nix-daemon
Related
I'm very new to Nix. I'd like to refer to project scripts in my shell.nix file, so that when I cd into my project directory I can refer to them by name, and I can keep them up-to-date whenever the sources change.
To learn how to do this, I created a very simple derivation for a shell script. Eventually I'd like to use other languages, but I'm starting simple. It looks like this:
project
nix
myScript
default.nix
builder.sh
shell.nix
# default.nix
{ pkgs ? import <nixpkgs> {} }:
pkgs.stdenv.mkDerivation rec {
name = "myScript";
echo = pkgs.coreutils + "/bin/echo";
builder = "${pkgs.coreutils}/bin/bash";
args = [ ./builder.sh ];
}
# builder.sh
$echo "$echo Hello world" > $out
When I run nix-build myScript.nix it creates a symlinked result file that looks like this:
/nix/store/3mfkgajns47hfv0diihzi2scwl4hm2fl-coreutils-9.1/bin/echo Hello world
I tried referencing this in my shell.nix file like this:
{ pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/bf972dc380f36a3bf83db052380e55f0eaa7dcb6.tar.gz") {} }:
let
myScript = import ./myScript {};
in
pkgs.mkShell {
buildInputs = [
myScript
];
shellHook = ''
echo Loading shell.nix
'';
}
But whenever I enter the projects directory and run the command `myScript, I get an error:
zsh: command not found: myScript
I already have direnv configured correctly, which I can confirm by adding other shell tools and checking their versions. So it's something wrong with my nix files.
I'm almost certainly doing something wrong here. I know I can simplify this with pkgs.writeShellScriptBin, but the shell script is more a minimal example of what I want to get working. Eventually I'd use more complex derivations.
What I think is wrong
I think the myScript derivation or builder is doing something wrong. It does create the expected output file (i.e. I can chmod +x and run it, and it works) but I suspect I need to tell nix how to run it? I'm not sure. And also I might be importing the derivation incorrectly.
This is a problem with your default.nix, not your shell.nix.
For mkShell to work with buildInputs as you intend, you need $out to be a directory with an $out/bin/myScript, not a file on its own. nixpkgs has a helper that will do this for you, in https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/trivial-builders.nix --
# default.nix; no builder.sh needed
{ pkgs ? import <nixpkgs> {} }:
pkgs.writeShellScript "myScript" ''
echo "Hello world" # use the bash-builtin echo, not the external coreutils one
'';
I haven't found any info about handling temporary files in Nix derivations.
I found $TMP and $TMPDIR env vars, but they both point just to /tmp, which is system global.
{
pkgs ? import <nixpkgs> {}
}:
pkgs.stdenv.mkDerivation {
pname = "show-tmp"
version = "0.1.0";
src = ./.;
configurePhase = ''
echo "tmp = $tmp; TMP = $TMP; TMPDIR = $TMPDIR"
'';
buildPhase = '':'';
installPhase = '':'';
}
Variable $tmp is not defined inside mkDerivation. I would expect such thing, because other derivation scope vars follow low case style such as $out.
The problem with /tmp is obvious - it is global directory.
I need to worry about collisions and cleaning.
My derivation-hook archives a big folder tree.
If you're on Linux, don't worry. The Nix sandbox will give your build its own empty /tmp. It is removed when your derivation is done.
On macOS, $TMP and $TMPDIR are taken care of but /tmp is a potential problem.
How Nix creates a private /tmp on Linux
macOS Darwin, where Nix was installed in early 2020:
nix-build --expr 'with import <nixpkgs> {}; runCommand "hi" {} "echo a > /tmp/a; ls -al /tmp; sleep 1;"'
ls -al /private/tmp/
...
-rw-r--r-- 1 nixbld1 wheel 2 May 19 12:49 a
...
So, finally starting to get a stable nix environment that I can basically do all of my development in. Hooray!
Now I want to make it reproducible, as in yarn.lock (for those familiar with npm/yarn in javascript land) or Pipfile.lock (very similar for Python).
Basically the idea is that I would have a way to generate a similar lock file whenever I run nix-env -if my-env.nix, or after running this command, if that is how it would work. From this lock file, I could then exactly restore my nix profile, down to the exact versions of dependencies and sub-dependencies of the installed profile. This could be checked into git or whatever after testing out new improvements, and so a record of the environment would be maintained.
It seems to me this would be one of the most obvious use cases for Nix, and one of the major advantages over just using Docker (though the two aren't mutually exclusive), so I apologize if I've missed some relevant documentation.
What you're probably looking for is a shell.nix file like this:
let
pkgs = import (fetchTarball {
url = "https://github.com/NixOS/nixpkgs/archive/696c6bed4e8e2d9fd9b956dea7e5d49531e9d13f.tar.gz";
sha256 = "1v3yrpj542niyxp0h3kffsdjwlrkvj0mg4ljb85d142gyn3sdzd4";
}) {};
in pkgs.mkShell {
buildInputs = with pkgs; [
git
hello
];
}
Upon calling nix-shell (which by default uses the shell.nix file in the current directory), you'll be in an environment with git and hello from the specific given nixpkgs revision. This can be reproduced among all nix users (okay almost*). I can really recommend using shell.nix files for all development.
Alternatively, there's also the lesser known -r flag to nix-env, which states that
--remove-all, -r
Remove all previously installed packages first. This is equivalent to running nix-env -e '.*' first, except that everything happens in a single transaction.
You can effectively use it to replace the stateful ~/.nix-profile/manifest.nix. Create a file env.nix containing:
let
pkgs = import <nixpkgs> {};
in {
inherit (pkgs) git hello;
}
Now running nix-env -ir env.nix will install exactly git and hello and remove everything else, so you can reproduce your nix-env installations with this single file. To install additional things: Add it to the file and run the command again. You can also pin nixpkgs to a specific version as in the file above to not care about your nix-channel setup (which is also stateful).
Edit: It's also possible to get some packages from your channel and some of a specific nixpkgs revision:
let
pkgs = import <nixpkgs> {};
fixed = import (fetchTarball {
url = "https://github.com/NixOS/nixpkgs/archive/696c6bed4e8e2d9fd9b956dea7e5d49531e9d13f.tar.gz";
sha256 = "1v3yrpj542niyxp0h3kffsdjwlrkvj0mg4ljb85d142gyn3sdzd4";
}) {};
in {
inherit (pkgs) git;
inherit (fixed) hello;
}
*: The nix config, overlays and your system (Linux/Mac) can still influence this. It's a good idea to use import <nixpkgs> { config = {}; overlays = []; } for development to avoid this.
After many suggestions from folks on IRC, I was able to put together the following script, which takes a nix expression as its only argument, and copies the derivation file and records the nixpkgs versions locally while installing the specified environment:
#!/bin/bash
if [ -z "$1" ] || [ "${1: -4}" != ".nix" ] || [ ! -f "$1" ]
then
echo "No .nix file supplied"
exit -1
fi
ENV_DRV=$(nix-instantiate "$1")
cp "$ENV_DRV" ./env_backup.drv
chmod u+rw ./env_backup.drv
nix-env --set "$ENV_DRV"
NIXPKGS_VERSION=$(nix-instantiate --eval '<nixpkgs/lib>' -A version)
NIXOS_VERSION=$(nix-instantiate --eval '<nixos/lib>' -A version)
printf "nixpkgs: %s\\nnixos: %s" "$NIXPKGS_VERSION" "${NIXOS_VERSION}" > .nix_versions
Caveat: your nix expression should have the nix package in it, since we are using nix-env --set.
I haven't tried using a copied .drv file yet, but it somehow needs to be restored into the nix store; I've mainly included it as a last resort and for debugging. The output into .nix_versions should be more helpful, as these contain git commit hashes (after the last ".") that can be used to employ the correct revision of nixpkgs (thanks to infinisil on IRC):
pkgs = import "${(import <nixpkgs> {}).fetchFromGitHub { owner = "NixOS"; repo = "nixpkgs"; rev = "<your revision hash>"; sha256 = "<the hash of the output>"; }}" {}
To fill in the hash, either supply an incorrect hash to get the correct hash back, or just use the following: nix-prefetch-url --unpack github.com/nixos/nixpkgs/archive/<revision>.tar.gz.
Or, if manually checking out nixpkgs, you can just do e.g.:
with import ((builtins.getEnv "HOME") + "/workspace/nixpkgs") { }; # or:
with import "../nixpkgs" { }; # or similar
I haven't tested this sort of thing with nix-shell yet, but hope to do so soon.
I'm packaging a node script with an external dependency (GraphicsMagick), and when attempting to override the derivation generated from node2nix I get the error:
wrapProgram: command not found
The following text goes into detail of what I've tried to solve this error.
Reproducing the problem from scratch
I've created a minimal git repository that reproduces this problem if you'd just like to take a look there. Else, the steps to reproduce the problem are below.
Initial Shell Session:
In an empty directory, run:
npm init -y
npm install --save gm
curl https://i.imgur.com/addSfQi.jpg > image.png
(npm version: 5.6.0 & node version v8.9.4)
Create index.js
#!/usr/bin/env node
const path = require("path"); // node.js builtin
const gm = require("gm"); // GraphicsMagick module
const imagePath = path.join(__dirname, "image.png");
// Flip image horizontally and write to disk
gm(imagePath)
.flop()
.write(imagePath, error => {
console.log("error:", error);
});
Add a "bin" section to package.json:
"bin": "index.js"
Generate *.nix files with node2nix
node2nix -8 -l package-lock.json
Create override.nix
{ pkgs ? import <nixpkgs> {}
, system ? builtins.currentSystem
}:
let
nodePackages = import ./default.nix {
inherit pkgs system;
};
in
nodePackages // {
package = nodePackages.package.override (oldAttrs: {
postInstall = ''
wrapProgram "$out/bin/test-nodejs-gm-nixpkg" --prefix PATH : "${pkgs.graphicsmagick}/bin"
'';
});
}
Build nix package
nix-build override.nix -A package
The above fails with:
/nix/store/*/setup: line 95: wrapProgram: command not found
Helpful Resources
node2nix git repository - includes some basic examples.
example override in nixpkgs - example of how nixpkgs uses wrapProgram in postInstall with files generated by node2nix.
wrapProgram is contained within the makeWrapper package.
nativeBuildInputs = oldAttrs.nativeBuildInputs or [] ++ [ pkgs.makeWrapper ];
As mentioned by #ppb in the comments.
I've just started using the Nix package manager on OSX and I'm attempting to create my first package for the pass binary (https://www.passwordstore.org) - which is not available in the Nixpkgs repository.
I'm attempting to specify a runtime dependency (getopt), however this doesn't appear to be available when the binary is used.
This is my packages's default.nix:
{ pkgs ? import <nixpkgs> {} }:
with pkgs;
let
version = "1.7.1";
in {
pass = stdenv.mkDerivation rec {
name = "pass-${version}";
src = fetchurl {
url = "https://git.zx2c4.com/password-store/snapshot/password-store-1.7.1.tar.xz";
sha256 = "0scqkpll2q8jhzcgcsh9kqz0gwdpvynivqjmmbzax2irjfaiklpn";
};
buildInputs = [ stdenv makeWrapper];
installPhase = ''
make install PREFIX=$out/artifact
makeWrapper $out/artifact/bin/pass $out/bin/pass \
--set PATH ${stdenv.lib.makeBinPath [ getopt ]}
'';
meta = {
homepage = "https://www.passwordstore.org";
description = "The standard unix password manager";
license = stdenv.lib.licenses.gpl2Plus;
};
};
}
I can successfully build this package (nix-build --show-trace) and install it (nix-env -i ./result).
Listing the runtime dependencies for my package shows getopt listed:
nix-store -qR $(which pass)
...
/nix/store/c5swmygzc0kmvpq6cfkvwm2yz1k57kqy-getopt-1.1.4
However when I come to use the binary (pass init my-key) I get the following error:
/nix/store/...-pass-1.7.1/artifact/bin/pass: line 302:
/usr/local/bin/getopt: No such file or directory
Can anyone advise what I'm doing wrong?
Thanks
It looks like getopt gets a special treatment. The darwin.sh script looks for it using brew and port and falls back to /usr/local. That's why the (correct) wrapper has no effect.
So the solution seems to be, to make it look for getopt in PATH, which is provided by the wrapper script. You can probably make it as simple as GETOPT=getopt (which is similar to openbsd.sh)
For patching source code, see the NixPkgs documentation
After running nix-build, you should run cat result/bin/pass to look at your wrapper script and make sure it looks OK. It should be a shell script that sets the PATH to include getopt and then calls result/artifact/bin/pass.
Then try running the wrapper script. Note that the wrapper should be in result/bin, not result/artifact/bin.