d367b8e787
For example,
$ nix-build --hash -A nix-repl.src
will build the fixed-output derivation nix-repl.src (a fetchFromGitHub
call), but instead of *verifying* the hash given in the Nix
expression, it prints out the resulting hash, and then moves the
result to its content-addressed location in the Nix store. E.g
build produced path ‘/nix/store/504a4k6zi69dq0yjc0bm12pa65bccxam-nix-repl-8a2f5f0607540ffe56b56d52db544373e1efb980-src’ with sha256 hash ‘0cjablz01i0g9smnavhf86imwx1f9mnh5flax75i615ml71gsr88’
The goal of this is to make all nix-prefetch-* scripts unnecessary: we
can just let Nix run the real thing (i.e., the corresponding fetch*
derivation).
Another example:
$ nix-build --hash -E 'with import <nixpkgs> {}; fetchgit { url = "https://github.com/NixOS/nix.git"; sha256 = "ffffffffffffffffffffffffffffffffffffffffffffffffffff"; }'
...
git revision is
|
||
|---|---|---|
| .. | ||
| boost | ||
| bsdiff-4.3 | ||
| download-via-ssh | ||
| libexpr | ||
| libmain | ||
| libstore | ||
| libutil | ||
| nix-collect-garbage | ||
| nix-daemon | ||
| nix-env | ||
| nix-hash | ||
| nix-instantiate | ||
| nix-log2xml | ||
| nix-prefetch-url | ||
| nix-store | ||