Before this change, buildRustCrate always called rustc with
--extern libName=[...]libName[...]
However, Cargo permits using a different name under which a dependency
is known to a crate. For example, rand 0.7.0 uses:
[dependencies]
getrandom_package = { version = "0.1.1", package = "getrandom", optional = true }
Which introduces the getrandom dependency such that it is known as
getrandom_package to the rand crate. In this case, the correct extern
flag is of the form
--extern getrandom_package=[...]getrandom[...]
which is currently not supported. In order to support such cases, this
change introduces a crateRenames argument to buildRustCrate. This
argument is an attribute set of dependencies that should be renamed. In
this case, crateRenames would be:
{
"getrandom" = "getrandom_package";
}
The extern options are then built such that if the libName occurs as
an attribute in this set, it value will be used as the local
name. Otherwise libName will be used as before.
In combination with carnix we can now build crates that require a
specific edition of rust features. A few crates started requiring that
already and having this in nixpkgs is just logical.
This commit adds test based on real-world crates (brotli).
There were a few more edge cases that were missing beforehand. Also it
turned out that we can get rid of the `finalBins` list since that will
now be handled during runtime.
The build expression got quiet large over time and to make it a bit
easier to grasp the different scripts involved in the build are now
separated from the nix file.
Daniël de Kok
Peter Kolloch
Pierre-Étienne Meunier
Andreas Rammhold
Darius Jahandarie
Pierre-Etienne Meunier