It's a common pattern in Nixpkgs to want to emit a warning in certain
cases, but not actually change behaviours.
This is often expressed as either
if cond then lib.warn "Don't do that thing" x else x
Or
(if cond then lib.warn "Don't do that thing" else lib.id) x
Neither of which really expresses the intent here, because it looks
like 'x' is being chosen conditionally.
To make this clearer, I introduce a "warnIf" function, which makes it
clear that the only thing being affected by the condition is whether
the warning is generated, not the value being returned.
These are all the architectures supported by Nixpkgs on other
platforms, that are also supported by NetBSD. (So I haven't added
any architectures that are new to Nixpkgs here, even though NetBSD
supports some that we don't have.)
The previous mess was partially grouped by OS, and partially grouped
by architecture, which made it very difficult to know where to add new
entries.
I've chosen to group by OS entirely, because OSes are likely to
maintain exhaustive lists of supported architectures, but it's far
less likely we'd be able to find exhaustive lists of supported OSes
for every architecture.
When in the presence of worktrees, it happens that /commondir has a
trailing slash.
In these circumstances, it can lead to `lib.pathType` being passed paths
like `/foo/bar/.git/`, which in turn lead to
`error: attribute '.git' missing`.
With this change, we now make sure send properly-formatted paths to all
other functions.
This, in particular, fixes running NixOS tests on worktrees created by
libgit2 on my machine. (Worktrees created by git itself appear to not
hit the issue.)
I recently wrote some Nix code where I wrongly set a value to an option
which wasn't an actual option, but an attr-set of options. The mistake I
made can be demonstrated with an expression like this:
{
foo = { lib, pkgs, config, ... }: with lib; {
options.foo.bar.baz = mkOption {
type = types.str;
};
config.foo.bar = 23;
};
}
While it wasn't too hard to find the cause of the mistake for me, it was
necessary to have some practice in reading stack traces from the module
system since the eval-error I got was not very helpful:
error: --- TypeError --------------------------------------------------------- nix-build
at: (323:25) in file: /nix/store/3nm31brdz95pj8gch5gms6xwqh0xx55c-source/lib/modules.nix
322| foldl' (acc: module:
323| acc // (mapAttrs (n: v:
| ^
324| (acc.${n} or []) ++ f module v
value is an integer while a set was expected
(use '--show-trace' to show detailed location information)
I figured that such an error can be fairly confusing for someone who's
new to NixOS, so I decided to catch this case in th `byName` function in
`lib/modules.nix` by checking if the value to map through is an actual
attr-set. If not, a different error will be thrown.
Usually we ensure using the mapAttrs call wrapping the license set that
every license has an associated shortName. A change related to legacy
aliases most likely introduced the removal of the shortName attribute
for all the legacy license names by splitting the set into two sets
connected by a record update operator -- leading to mapAttrs only
affecting the first set.
Since it used to be a valid assumption to have that every license had a
shortName attribute, we reintroduce this attribute for the legacy
aliases as well.
Forcing the module to be builtin breaks 5.10, which wants to compile it as a
module (probably due to dependencies). There doesn't seem to be a need to have
it builtin anymore, so we can just remove the override.
In 9c213398b3 kernelPreferBuiltin was
moved/renamed to linux-kernel.preferBuiltin. However, for
armv7l-hf-multiplatform the new option was written with an uppercase P,
which made the kernel build process ignore it.
This reverts commit d9a7d03da8.
Reason for this is that it actually doesn't migitate the issue on nix
stable for another reason: builtins.tryEval doesn't prevent the error
generated by builtins.functionArgs from halting evaluation:
> builtins.tryEval (builtins.functionArgs builtins.functionArgs)
error: 'functionArgs' requires a function, at (string):1:19
Thus it seems that there is no workaround to make
lib.generators.toPretty work with nix stable and primops since there is
no way to distinguish between primops and lambdas in nix.
An high level example case of this problem occuring can be found below:
nix-repl> lib.generators.toPretty {} (lib.concatStringsSep "\n")
error: 'functionArgs' requires a function, at /home/lukas/src/nix/nixpkgs/lib/trivial.nix:334:42
However this does not happen on other partially applied functions:
nix-repl> lib.generators.toPretty {} (lib.concatMapStringsSep "\n")
"<function>"
The issue, as it turns out is that while builtins are functions,
builtins.functionArgs throws if is passed a builtin or a partially
applied builtin:
nix-repl> lib.generators.toPretty {} builtins.toString
error: 'functionArgs' requires a function, at /home/lukas/src/nix/nixpkgs/lib/trivial.nix:334:42
nix-repl> lib.generators.toPretty {} (builtins.foldl' (a: b: a + b))
error: 'functionArgs' requires a function, at /home/lukas/src/nix/nixpkgs/lib/trivial.nix:334:42
I'm pretty sure this qualifies as a nix bug and should be filed
accordingly, but we can work around it in lib.generators.toPretty by
using tryEval and falling back to {} which functionArgs _should_ return
for builtins.
The nix behavior is inconsistent to say the least:
nix-repl> builtins.functionArgs builtins.functionArgs
error: 'functionArgs' requires a function, at (string):1:1
nix-repl> builtins.typeOf builtins.functionArgs
"lambda"
builtins.functionArgs (a: 1 + a)
{ }
nix-repl> builtins.typeOf (a: 1 + a)
"lambda"
PPC64 supports two ABIs: ELF v1 and v2.
ELFv1 is historically what GCC and most packages expect, but this is
changing because musl outright does not work with ELFv1. So any distro
which uses musl must use ELFv2. Many other platforms are moving to ELFv2
too, such as FreeBSD (as of v13) and Gentoo (as of late 2020).
Since we use musl extensively, let's default to ELFv2.
Nix gives us the power to specify this declaratively for the entire
system, so ELFv1 is not dropped entirely. It can be specified explicitly
in the target config, e.g. "powerpc64-unknown-linux-elfv1". Otherwise the
default is "powerpc64-unknown-linux-elfv2". For musl,
"powerpc64-unknown-linux-musl" must use elfv2 internally to function.
Now type checks the resulting function values and allows mkMerge and co.
Also indicates that the type check is done in the function body
Co-Authored-By: Robert Hensing <robert@roberthensing.nl>
