Setting the hash to null is a convenient way to bypass the hash check
while developing. It looks like the ability to do this was inadvertently
removed while adding vendor directory support.
This still checks that the user is explicitly setting the value but
allows null as a valid option.
This is to go to a reproducible image build.
Note without this options image are identical from the Docker point of
view but generated docker archives could have different hashes.
This is to improve image creation reproducibility. Since the nar
format doesn't support hard link, the tar stream of a layer can be
different if a dependency of a layer has been built locally or if it
has been fetched from a binary cache.
If the dependency has been build locally, it can contain hard links
which are encoded in the tar stream. If the dependency has been
fetched from a binary cache, the tar stream doesn't contain any hard
link. So even if the content is the same, tar streams are different.
Resolved the following conflicts (by carefully applying patches from the both
branches since the fork point):
pkgs/development/libraries/epoxy/default.nix
pkgs/development/libraries/gtk+/3.x.nix
pkgs/development/python-modules/asgiref/default.nix
pkgs/development/python-modules/daphne/default.nix
pkgs/os-specific/linux/systemd/default.nix
Existing "mips64el" should be "mipsel".
This is just the barest minimum so that nixpkgs can recognize them as
systems - although required for building individual derivations onto
MIPS boards, it is not sufficient if you want to actually build nixos on
those targets
Previously, cargoUpdateHook was meaningful as it was used
in
[`cargo-fetch-deps`](19d3cf81d3/pkgs/build-support/rust/fetch-cargo-deps (L71)).
However, this entire file was removed in
5f8cf0048e. As far as I can
tell, nothing in the code is using it, but it is still
being passed around:
https://github.com/NixOS/nixpkgs/search?q=cargoUpdateHook&type=Code&utf8=%E2%9C%93
There are, however, legitimate use cases for it. For example,
in some software, some dependencies are not locked in Cargo.toml
and this causes Cargo to try fetching another version of them.
This doesn't work well with vendoring crates.
This hook allows to inject patching or whatever necessary workarounds
in the crate vendoring process. I suppose that's what it was for
in there in the first place.
This patch restores this hook and makes it usable again.
