Charles Hall
c8cf70b601
Specifically, for errors where the provided and expected hashes differ. Also, I've updated `fetchTarball`'s docs to explain the allowed values for the `sha256` attribute. Change-Id: Ic9aa777dc0a3c1ccdb4c98048745067f529bd986
1.8 KiB
name, args, renameInGlobalScope
| name | args | renameInGlobalScope | |
|---|---|---|---|
| fetchTarball |
|
false |
Download the specified URL, unpack it and return the path of the
unpacked tree. The file must be a tape archive (.tar) compressed
with gzip, bzip2 or xz. The top-level path component of the
files in the tarball is removed, so it is best if the tarball
contains a single directory at top level. The typical use of the
function is to obtain external Nix expression dependencies, such as
a particular version of Nixpkgs, e.g.
with import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz") {};
stdenv.mkDerivation { … }
The fetched tarball is cached for a certain amount of time (1
hour by default) in ~/.cache/nix/tarballs/. You can change the
cache timeout either on the command line with --tarball-ttl
number-of-seconds or in the Nix configuration file by adding
the line tarball-ttl = number-of-seconds.
Note that when obtaining the hash with nix-prefetch-url the
option --unpack is required.
This function can also verify the contents against a hash. In that
case, the function takes a set instead of a URL. The set requires
the attribute url and the attribute sha256, e.g.
with import (fetchTarball {
url = "https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz";
sha256 = "sha256-QsrS6BEjO8ccwlmL1b7/5iPaemuM/Ibj9WWu7bKe98o=";
}) {};
stdenv.mkDerivation { … }
The sha256 attribute accepts Nix-style base32 sha256 hashes (e.g.
1jppksrfvbk5ypiqdz4cddxdl8z6zyzdb2srq8fcffr327ld5jj2), hashes
in SRI format (as shown above), and some other less common hash
algorithms and formats.
Not available in restricted evaluation mode.