That is, unless --file is specified, the Nix search path is
synthesized into an attribute set. Thus you can say
$ nix build nixpkgs.hello
assuming $NIX_PATH contains an entry of the form "nixpkgs=...". This
is more verbose than
$ nix build hello
but is less ambiguous.
Also, move a few free-standing functions into StoreAPI and Derivation.
Also, introduce a non-nullable smart pointer, ref<T>, which is just a
wrapper around std::shared_ptr ensuring that the pointer is never
null. (For reference-counted values, this is better than passing a
"T&", because the latter doesn't maintain the refcount. Usually, the
caller will have a shared_ptr keeping the value alive, but that's not
always the case, e.g., when passing a reference to a std::thread via
std::bind.)
The nixpkgs manual prescribes the use of values from stdenv.lib.licenses
for the meta.license attribute. Those values are attribute sets and
currently skipped when running nix-env with '--xml --meta'. This has the
consequence that also nixpkgs-lint will report missing licenses.
With this commit nix-env with '--xml --meta' will print all attributes
of an attribute set that are of type tString. For example the output for
the package nixpkgs.hello is
<meta name="license" type="strings">
<string type="url" value="http://spdx.org/licenses/GPL-3.0+" />
<string type="shortName" value="gpl3Plus" />
<string type="fullName" value="GNU General Public License v3.0 or later" />
<string type="spdxId" value="GPL-3.0+" />
</meta>
This commit fixes nixpkgs-lint, too.
It was strange to show "upgrading" when the version was getting lower.
This is left on "upgrading" when the versions are the same,
as I can't see any better wording.
Until now, if one explicitly installed a low-priority version,
nix-env --upgrade would downgrade it by default and even with --leq.
Let's never accept an upgrade with version not matching the upgradeType.
Additionally, let's never decrease the priority of an installed package;
you can use --install to force that.
Also refactor to use variable bestVersion instead of bestName,
as only version was used from it.
The value pointers of lists with 1 or 2 elements are now stored in the
list value itself. In particular, this makes the "concatMap (x: if
cond then [(f x)] else [])" idiom cheaper.
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!
The flag ‘--check’ to ‘nix-store -r’ or ‘nix-build’ will cause Nix to
redo the build of a derivation whose output paths are already valid.
If the new output differs from the original output, an error is
printed. This makes it easier to test if a build is deterministic.
(Obviously this cannot catch all sources of non-determinism, but it
catches the most common one, namely the current time.)
For example:
$ nix-build '<nixpkgs>' -A patchelf
...
$ nix-build '<nixpkgs>' -A patchelf --check
error: derivation `/nix/store/1ipvxsdnbhl1rw6siz6x92s7sc8nwkkb-patchelf-0.6' may not be deterministic: hash mismatch in output `/nix/store/4pc1dmw5xkwmc6q3gdc9i5nbjl4dkjpp-patchelf-0.6.drv'
The --check build fails if not all outputs are valid. Thus the first
call to nix-build is necessary to ensure that all outputs are valid.
The current outputs are left untouched: the new outputs are either put
in a chroot or diverted to a different location in the store using
hash rewriting.
This is equivalent to running ‘nix-env -e '*'’ first, except that it
happens in a single transaction. Thus, ‘nix-env -i pkgs...’ replaces
the profile with the specified set of packages.
The main motivation is to support declarative package management
(similar to environment.systemPackages in NixOS). That is, if you
have a specification ‘profile.nix’ like this:
with import <nixpkgs> {};
[ thunderbird
geeqie
...
]
then after any change to ‘profile.nix’, you can run:
$ nix-env -f profile.nix -ir
to update the profile to match the specification. (Without the ‘-r’
flag, if you remove a package from ‘profile.nix’, it won't be removed
from the actual profile.)
Suggested by @zefhemel.
This prevents some duplicate evaluation in nix-env and
nix-instantiate.
Also, when traversing ~/.nix-defexpr, only read regular files with the
extension .nix. Previously it was reading files like
.../channels/binary-caches/<name>. The only reason this didn't cause
problems is pure luck (namely, <name> shadows an actual Nix
expression, the binary-caches files happen to be syntactically valid
Nix expressions, and we iterate over the directory contents in just
the right order).
