From f35f9af78720cec098c5c2188bf34948b3a67c95 Mon Sep 17 00:00:00 2001 From: Keshav Kini Date: Thu, 3 Jun 2021 17:59:39 -0700 Subject: [PATCH] Improve explanation of NIX_PATH prefix syntax The previous wording seemed to imply that the "channel:" syntax would resolve to a github archive URL, which is not the case. --- doc/manual/src/command-ref/env-common.md | 42 +++++++++++++----------- 1 file changed, 23 insertions(+), 19 deletions(-) diff --git a/doc/manual/src/command-ref/env-common.md b/doc/manual/src/command-ref/env-common.md index b709ca9d1..6e2403461 100644 --- a/doc/manual/src/command-ref/env-common.md +++ b/doc/manual/src/command-ref/env-common.md @@ -10,35 +10,39 @@ Most Nix commands interpret the following environment variables: A colon-separated list of directories used to look up Nix expressions enclosed in angle brackets (i.e., ``). For instance, the value - + /home/eelco/Dev:/etc/nixos - + will cause Nix to look for paths relative to `/home/eelco/Dev` and `/etc/nixos`, in this order. It is also possible to match paths against a prefix. For example, the value - + nixpkgs=/home/eelco/Dev/nixpkgs-branch:/etc/nixos - + will cause Nix to search for `` in `/home/eelco/Dev/nixpkgs-branch/path` and `/etc/nixos/nixpkgs/path`. - + If a path in the Nix search path starts with `http://` or `https://`, it is interpreted as the URL of a tarball that will be downloaded and unpacked to a temporary location. The tarball must consist of a single top-level directory. For example, setting `NIX_PATH` to - - nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-15.09.tar.gz - - tells Nix to download the latest revision in the Nixpkgs/NixOS 15.09 - channel. - - A following shorthand can be used to refer to the official channels: - - nixpkgs=channel:nixos-15.09 - - The search path can be extended using the `-I` option, which takes - precedence over `NIX_PATH`. + + nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz + + tells Nix to download and use the current contents of the + `master` branch in the `nixpkgs` repository. + + The URLs of the tarballs from the official nixos.org channels (see + [the manual for `nix-channel`](nix-channel.md)) can be abbreviated + as `channel:`. For instance, the following two + values of `NIX_PATH` are equivalent: + + nixpkgs=channel:nixos-21.05 + nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz + + The Nix search path can also be extended using the `-I` option to + many Nix commands, which takes precedence over `NIX_PATH`. - `NIX_IGNORE_SYMLINK_STORE`\ Normally, the Nix store directory (typically `/nix/store`) is not @@ -50,7 +54,7 @@ Most Nix commands interpret the following environment variables: builds are deployed to machines where `/nix/store` resolves differently. If you are sure that you’re not going to do that, you can set `NIX_IGNORE_SYMLINK_STORE` to `1`. - + Note that if you’re symlinking the Nix store so that you can put it on another file system than the root file system, on Linux you’re better off using `bind` mount points, e.g., @@ -59,7 +63,7 @@ Most Nix commands interpret the following environment variables: $ mkdir /nix $ mount -o bind /mnt/otherdisk/nix /nix ``` - + Consult the mount 8 manual page for details. - `NIX_STORE_DIR`\