The option '--delete-generations Nd' deletes all generations older than N
days. However, most likely the user does not want to delete the
generation that was active N days ago.
For example, say that you have these 3 generations:
1: <30 days ago>
2: <15 days ago>
3: <1 hour ago>
If you do --delete-generations 7d (say, as part of a cron job), most
likely you still want to keep generation 2, i.e. the generation that was
active 7 days ago (and for most of the past 7 days, in fact).
This patch fixes this issue. Note that this also affects
'nix-collect-garbage --delete-older-than Nd'.
Thanks to @roconnor for noticing the issue!
This allows you to easily set up a build environment containing the
specified packages from Nixpkgs. For example:
$ nix-shell -p sqlite xorg.libX11 hello
will start a shell in which the given packages are present.
The tarball can now be unpacked anywhere. The installation script
uses "sudo" to create /nix if it doesn't exist. It also fetches the
nixpkgs-unstable channel.
This allows running nix-instantiate --eval-only without performing the
evaluation in readonly mode, letting features like import from
derivation and automatic substitution of builtins.storePath paths work.
Signed-off-by: Shea Levy <shea@shealevy.com>
Combined with the previous changes, stack traces involving derivations
are now much less verbose, since something like
while evaluating the builtin function `getAttr':
while evaluating the builtin function `derivationStrict':
while instantiating the derivation named `gtk+-2.24.20' at `/home/eelco/Dev/nixpkgs/pkgs/development/libraries/gtk+/2.x.nix:11:3':
while evaluating the derivation attribute `propagatedNativeBuildInputs' at `/home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/default.nix:78:17':
while evaluating the attribute `outPath' at `/nix/store/212ngf4ph63mp6p1np2bapkfikpakfv7-nix-1.6/share/nix/corepkgs/derivation.nix:18:9':
...
now reads
while evaluating the attribute `propagatedNativeBuildInputs' of the derivation `gtk+-2.24.20' at `/home/eelco/Dev/nixpkgs/pkgs/development/libraries/gtk+/2.x.nix:11:3':
...