I believe this change is wrong both theoretically and practically.
Theoretically, `null` is available on every platform, because
`buildInputs = [ null ];` always succeeds and never throws a platform
availability error. `null` should be handled consistently with packages
that have no explicit list of supported platforms, as it of course
has no such list itself.
Practically, we use `null` to represent libraries that are always
present on a platform and do not require a library (for instance,
because they are part of `libc` or the macOS SDK). This has been
used for a long time by `libintl` (on all non‐glibc platforms),
and is also now used by `libGL` and friends on Darwin. This change
broke the check SDL3 does for OpenGL availability on Darwin, causing
<https://github.com/NixOS/nixpkgs/issues/407056>, which had to be
worked around by <https://github.com/NixOS/nixpkgs/pull/409525>.
Both `libintl` and `libGL` should count as available on platforms
where their functionality is part of the standard build environment,
and a package that is completely unavailable and whose functionality
cannot be expected should not use `null`, as it should result in
errors if used in a dependency list on an unsupported platform.
I accept that overriding with `null` is often a useful way to disable
dependencies that don’t have explicit feature flags, but I do not
think that making it work better with feature flags conditioned on
availability is worth the inconsistency and problems caused by this
change. Packages can instead expose the relevant feature flags as
arguments that default to the `lib.meta.availableOn` check or, if they
want to keep an “override the dependency to `null`” interface,
insert an explicit `pkg != null && …` check.
Additionally, the pull request was merged over a week after all
breaking changes were restricted for the 25.05 release. I believe that
the potential problems of dealing with the effects of this change for
an entire release cycle – the first release cycle where `libGL` is
`null` on Darwin, a change I made before the deadline and before this
change to `lib.meta.availableOn` – offset the risks of backporting
this revert at such a late stage.
It will cause overrides to backwards‐incompatibly revert to the
behaviour they had before the change, but since such overrides were
not possible until a few weeks ago, I hope that is an acceptable risk
compared to the potential issues leaving this in the release can
cause, given that it was merged after the deadline and has already
broken an existing construction in Nixpkgs.
This reverts commit 9338d924db.
To fix overriding packages that checks for platform compatibility, like pipewire.
`pipewire` contains the following logic to enable support for ldac depending on library platform compatibility:
```nix
ldacbtSupport = lib.meta.availableOn stdenv.hostPlatform ldacbt
```
Which is used later in the expression to create a Meson flag:
```nix
(lib.mesonEnable "bluez5-codec-ldac" (bluezSupport && ldacbtSupport))
```
This means that attempting to build `pipewire` without `ldacbt` like:
```nix
pipewire.override {
ldacbt = null;
}
```
will fail because the the Meson flag indicates the feature should be enabled, but the library is passed to `buildInputs` as `null`.
Format all Nix files using the officially approved formatter,
making the CI check introduced in the previous commit succeed:
nix-build ci -A fmt.check
This is the next step of the of the [implementation](https://github.com/NixOS/nixfmt/issues/153)
of the accepted [RFC 166](https://github.com/NixOS/rfcs/pull/166).
This commit will lead to merge conflicts for a number of PRs,
up to an estimated ~1100 (~33%) among the PRs with activity in the past 2
months, but that should be lower than what it would be without the previous
[partial treewide format](https://github.com/NixOS/nixpkgs/pull/322537).
Merge conflicts caused by this commit can now automatically be resolved while rebasing using the
[auto-rebase script](8616af08d9/maintainers/scripts/auto-rebase).
If you run into any problems regarding any of this, please reach out to the
[formatting team](https://nixos.org/community/teams/formatting/) by
pinging @NixOS/nix-formatting.
- Expose `lib.licensesSpdx`
- Create bindings for the needed internal functions
- Mention that some SPDX licenses might be missing (in the future I hope
we can autogenerate the Nixpkgs license list from some SPDX endpoint
Add lib.meta.getLicenseFromSpdxIdOr as a variant of
lib.meta.getLicenseFromSpdxId that explicitly state the default
(fallback) value if there's no license matching the given SPDX ID.
Before this commit, getExe assumes that if `meta.mainProgram` is unset,
it has a main program that's named after the package name.
While this is probable, it leads to a bad error when the assumption does
not hold. If the user called `getExe` themselves, they might narrow down
the location of the assumption quite easily, but if that's not the case,
they'll have to go down the rabbit hole to figure out what went wrong.
For example, a NixOS module may use `lib.getExe` on a package-typed option
which is then used in the system configuration. This then typically leads
to a failure *after* deployment, which is bad, and it's quite likely that
the user will debug the package output contents before digging through the
NixOS module, which is bad.
Furthermore the `getExe` call is rather inconspicuous as it does not
contain something like "/bin/foo", which is bad.
Also modules can be hard to read for a newbie, which is bad.
All of this can be avoided by requiring `meta.mainProgram`.
Many packages already have the attribute, and I would expect 80% of
`getExe` usages to be covered by 20% of packages, because plenty of
packages aren't used with `getExe` anyway.
Finally we could make an effort to set `mainProgram` semi-automatically
using `nix-index`.
`hasUnsupportedPlatform` was not updated with #37395, so it does not
understand attrsets in `meta.[bad]platforms`. In particular,
attrsets in `meta.badPlatforms` will "fail open" and be ignored.
Let's use `lib.meta.availableOn` instead of duplicating its logic.
Thanks to @alyssais for [noticing][1].
[1][https://github.com/NixOS/nixpkgs/pull/194148#discussion_r990817610]
Co-authored-by: sternenseemann <sternenseemann@systemli.org>
Move function spdxLicense, internally used in yarn2nix
to lib/meta.nix, and
rename to getLicenseFromSpdxId
A similar function is implemented in poetry2nix,
but the one originally in yarn2nix seems beter.
since it falls back to an license-like attrset
for mismatched case
instead of a plain string
The isKexecable flag treated Linux without kexec as just a normal
variant, when it really should be treated as a special case incurring
complexity debt to support.
This does break the API of being able to import any lib file and get
its libs, however I'm not sure people did this.
I made this while exploring being able to swap out docFn with a stub
in #2305, to avoid functor performance problems. I don't know if that
is going to move forward (or if it is a problem or not,) but after
doing all this work figured I'd put it up anyway :)
Two notable advantages to this approach:
1. when a lib inherits another lib's functions, it doesn't
automatically get put in to the scope of lib
2. when a lib implements a new obscure functions, it doesn't
automatically get put in to the scope of lib
Using the test script (later in this commit) I got the following diff
on the API:
+ diff master fixed-lib
11764a11765,11766
> .types.defaultFunctor
> .types.defaultTypeMerge
11774a11777,11778
> .types.isOptionType
> .types.isType
11781a11786
> .types.mkOptionType
11788a11794
> .types.setType
11795a11802
> .types.types
This means that this commit _adds_ to the API, however I can't find a
way to fix these last remaining discrepancies. At least none are
_removed_.
Test script (run with nix-repl in the PATH):
#!/bin/sh
set -eux
repl() {
suff=${1:-}
echo "(import ./lib)$suff" \
| nix-repl 2>&1
}
attrs_to_check() {
repl "${1:-}" \
| tr ';' $'\n' \
| grep "\.\.\." \
| cut -d' ' -f2 \
| sed -e "s/^/${1:-}./" \
| sort
}
summ() {
repl "${1:-}" \
| tr ' ' $'\n' \
| sort \
| uniq
}
deep_summ() {
suff="${1:-}"
depth="${2:-4}"
depth=$((depth - 1))
summ "$suff"
for attr in $(attrs_to_check "$suff" | grep -v "types.types"); do
if [ $depth -eq 0 ]; then
summ "$attr" | sed -e "s/^/$attr./"
else
deep_summ "$attr" "$depth" | sed -e "s/^/$attr./"
fi
done
}
(
cd nixpkgs
#git add .
#git commit -m "Auto-commit, sorry" || true
git checkout fixed-lib
deep_summ > ../fixed-lib
git checkout master
deep_summ > ../master
)
if diff master fixed-lib; then
echo "SHALLOW MATCH!"
fi
(
cd nixpkgs
git checkout fixed-lib
repl .types
)
Meta attributes types are now enforce as of commit
90b9719f4f,
so ensure meta.priority is always set to an integer.
This fixes evaluation of `linuxPackages_latest.virtualbox`
(the impetus for this commit)
and other packages that use lowPrio or hiPrio.
I.e. append a suffix *before* the version, rather than after. So we
get "sqlite-interactive-3.8.0.2" instead of
"sqlite-3.8.0.2-interactive". The latter is broken since nix-env just
sees it the suffix as part of the version, so "nix-env -u" will
happily upgrade "sqlite-3.8.0.2-interactive" to "sqlite-3.9".
Nix-env always wants to install all outputs of a derivation, but this
failed for openjdk/openjre because openjdk has some symlinks (such as
bin/java) to openjre. Also, it prevents installing the openjre
without the openjdk. So as a workaround, mess with the "outputs"
attribute to fool nix-env.
Also, give openjre a separate name and description.
Fixes#1535.
