Otherwise, if the upstream mirror changes (rather than deletes) a
file, then tarballs.nixos.org won't be used even if it has a copy of
the original file, and so we'll get a hash mismatch.
Emacs packages are commonly distributed as single .el files. This
unpackCmd handles them correctly and sets up sourceRoot. Other sources
are treated in the default manner.
If "fetcher" is a string, then Nix will execute it with bash already, so
the additional bash argument in that string was redundant and apparently
causes trouble on non-Linux platforms.
Hopefully fixes https://github.com/NixOS/nixpkgs/issues/11496.
The list we had before contained a lot of junk, i.e. sites that were no
longer online or no longer in sync. The new list of sites comes from
https://gnupg.org/download/index.html.
The script's shebang depends on /usr/bin/env, which we don't have in chroot
environments. This patch remedies the fallout from ade9f7167dd1fec6, which
fixed https://github.com/NixOS/nixpkgs/issues/11284.
This reverts commit 2441e002e26d60e62306ae03a2c0d42fe156f129. The
motivation for removing them was not very convincing. Also, we need
3.14 on some Hydra build machines.
It turns out that cargo implicitly depends on rustc at runtime: even
`cargo help` will fail if rustc is not in the PATH.
This means that we need to wrap the cargo binary to add rustc to PATH.
However, I have opted into doing something slightly unusual: instead of
tying down a specific cargo to use a specific rustc (i.e., wrap cargo so
that "${rustc}/bin" is prefixed into PATH), instead I'm adding the rustc
used to build cargo as a fallback rust compiler (i.e., wrap cargo so
that "${rustc}/bin" is suffixed into PATH). This means that cargo will
prefer to use a rust compiler that is in the default path, but fallback
into the one used to build cargo only if there wasn't any rust compiler
in the default path.
The reason I'm doing this is that otherwise it could cause unexpected
effects. For example, if you had a build environment with the
rustcMaster and cargo derivations, you would expect cargo to use
rustcMaster to compile your project (since rustcMaster would be the only
compiler available in $PATH), but this wouldn't happen if we tied down
cargo to use the rustc that was used to compile it (because the default
cargo derivation gets compiled with the stable rust compiler).
That said, I have slightly modified makeRustPlatform so that a rust
platform will always use the rust compiler that was used to build cargo,
because this prevents mistakenly depending on two different versions of
the rust compiler (stable and unstable) in the same rust platform,
something which is usually undesirable.
Fixes#11053
