It looks like https://github.com/NixOS/nixpkgs/pull/88248 broke the
build for zig.
The error you get when building zig on the current master branch is:
```
Scanning dependencies of target zig_build_libstage2
: CommandLine Error: Option 'polly' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options
make[2]: *** [CMakeFiles/zig_build_libstage2.dir/build.make:77: CMakeFiles/zig_build_libstage2] Error 1
make[1]: *** [CMakeFiles/Makefile2:252: CMakeFiles/zig_build_libstage2.dir/all] Error 2
make: *** [Makefile:150: all] Error 2
```
The patch that added polly into some build args was likely necessary
only for LLVM 10.0.0 and when that was updated to 10.0.1 it stopped
working or became unnecessary. With this patch removed, zig builds fine
and passes the tests.
This adds a warning to the top of each “boot” package that reads:
Note: this package is used for bootstrapping fetchurl, and thus cannot
use fetchpatch! All mutable patches (generated by GitHub or cgit) that
are needed here should be included directly in Nixpkgs as files.
This makes it clear to maintainer that they may need to treat this
package a little differently than others. Importantly, we can’t use
fetchpatch here due to using <nix/fetchurl.nix>. To avoid having stale
hashes, we need to include patches that are subject to changing
overtime (for instance, gitweb’s patches contain a version number at
the bottom).
nixpkgs already has Inform 7, which is a lovely design system for creating interactive fiction (text adventures) using a natural language compiler and a rich IDE. However, underlying Inform 7 is a C-like language, Inform 6, which has a much simpler toolchain and its own compiler and standard libraries, which I have packaged for nix here.
This is needed for cross-compiling for LLVM.
After https://github.com/NixOS/nixpkgs/pull/94088, we still need some
of these, so I’ve whitelisted those that are in binutils.
/cc @DavidTruby
These llvm-prefixed utilities are not drop-in replacements for the utilities
with similar names, they are specifically for operating on LLVM IR files.
Symlinking these without the prefix causes incompatibilities with tools that
expect diff, as and others to behave normally.
