The `importApply` docs reference using the `_key` attr along with
`importApply` or `_file`, however the actual attr name used by the
module system is `key`.
The new implementation of `mapAttrsToList` is simpler than the previous one, avoiding an extra string conversion. Benchmarking shows a slight performance improvement. See the discussion here: https://discourse.nixos.org/t/another-implementation-of-mapattrstolist
Additionally, I searched nixpkgs for expressions equivalent to the old `mapAttrsToList` and replaced them with direct calls to the new implementation.
To fix overriding packages that checks for platform compatibility, like pipewire.
`pipewire` contains the following logic to enable support for ldac depending on library platform compatibility:
```nix
ldacbtSupport = lib.meta.availableOn stdenv.hostPlatform ldacbt
```
Which is used later in the expression to create a Meson flag:
```nix
(lib.mesonEnable "bluez5-codec-ldac" (bluezSupport && ldacbtSupport))
```
This means that attempting to build `pipewire` without `ldacbt` like:
```nix
pipewire.override {
ldacbt = null;
}
```
will fail because the the Meson flag indicates the feature should be enabled, but the library is passed to `buildInputs` as `null`.
lib.strings.escapeC produces single‐digit hexadecimal strings for
character values ≤ 15, which results in an ambiguity. If the following
character is a hex digit, it will be interpreted as being part of the
escape sequence.
systemd, which also relies on C‐style escape sequences, does not
decode single‐digit sequences at all, even if unambiguous.
Padding the hexadecimal string with "0" avoids this problem.
qemu architecture names are fixed — we're using uname here just
because it's more likely to be correct than CPU name (see e.g. POWER).
This means that aarch64 is always called aarch64, even on Darwin where
uname reports arm64.
Fixes: 61582c7043 ("lib/systems: use Darwin architecture names for `config` and `uname`")
So we are adding a simplified version that builds a monolithic nix binary to get finished
in time for the release. Afterwards we will switch to the modular build again.
