The code of `lib.closePropagation` was internally using a
recursion on the dependencies and returns all the derivation directly or
indirectly referenced by buildInputs.
`lib.closeProgation` is implemented in pure nix and uses an unique
function for list which is quadratic and does "true" equality, which
needs deep set comparison.
Instead, we use the `builtins.genericClosure` which is implemented as a
builtin and uses a more efficient sorting feature.
Note that `genericClosure` needs a `key` to discriminate the values, we
used the `outPath` which is unique and orderable.
On benchmarks, it performs up to 15x time faster on a benchmark related
to haskellPackages.ghcWithPackages.
Move already implemented functionality to the upper level so
it could be used in a more generic way.
Signed-off-by: Ivan Nikolaenko <ivan.nikolaenko@unikie.com>
This brings two benefits:
1. The complete list of collisions is printed in the whenever any colliding
attribute is accessed.
2. The sets are intersected using a C++ primitive, which runs in O(n) time
(intersecting pre-sorted lists) with small constants rather than interpreted
Nix code.
Thanks to @toonn for prompting this improvement.
```
nix-repl> pkgsCross.arm-embedded.stdenv.hostPlatform.emulatorAvailable pkgsCross.arm-embedded.buildPackages
false
nix-repl> pkgsCross.aarch64-multiplatform.stdenv.hostPlatform.emulatorAvailable pkgsCross.aarch64-multiplatform.buildPackages
true
```
will be useful for stuff like handling https://github.com/NixOS/nixpkgs/issues/187109
deprecate literalDocBook by adding a warning (that will not fire yet) to
its uses and other docbook literal strings by adding optional warning
message to mergeJSON.
The comment in lib/systems/default.nix for uname.processor indicates that it
should match `uname -p`. I tried that command and found that it reports
`unknown` on all of these machines:
- `x86_64-linux`
- `aarch64-linux`
- `mips64el-linux`
- `powerpc64le-linux`
The command `uname -m` reports the expected value on all of the above.
I think the comment is wrong. So I fixed it.
This attr provides the location of each definition.
This is particularly useful for introspecting options of type
`attrsOf`. E.g., it allows finding the location of a systemd
service definition by parsing
`options.systemd.services.definitionsWithLocations`.
This is particularly useful for disabling modules defined in a flake.
Example:
disabledModules = [ "${flake}/modules/mymodule.nix" ];
Previously, absolute string paths were internally prepended with `modulesPath`,
which caused the module filtering to fail.
