See docs.
Follow-up work:
- Existing packages should be converted
- `defaultPkgConfigPackages` should assert on `meta.pkgConfigModules`
and let `tests.pkg-config` alone test the build results.
CC @sternenseemann
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
platform.uname.processor seems to be what we want in many more cases
than what we were using before — it does the right thing for aarch64,
x86_64, riscv32, riscv64, mips, mips64, powerpc, and powerpc64 (the
latter three of which were broken before).
This fixes cross-compilation of systemd for PowerPC/POWER platforms.
Derivations listed as disallowedReferences or disallowedRequisites,
currently end up as build-time dependencies.
This is problematic since the disallowed derivations will be built by nix as
build-time dependencies, while those derivations might take a very long time
to build, or might not even build successfully on the platform used.
However, in order to scan for disallowed references in the final output,
knowing the out path is sufficient, and the out path can be calculated from
the derivation without needing to build it, saving time and resources.
While the problem is less severe for allowedReferences and allowedRequisites,
since we want the derivation to be built eventually, we would still like to
get the error early and without having to wait while nix builds a derivation
that might not be used (e.g. if we listed the wrong one).
A few potentially disruptive changes:
- binutils does not embed ${binutils-unwrapped}/lib as a default library
search path anymore. This will cause link failures for -lbfd -lopcodes
users that did not declare their dependency on those libraries. They
will need to add `libbfd` and `libopcodes` attributes to build inputs.
- `libbfd` and `libopcodes` attributes now just reference
`binutils-unwrapped.{dev,lib}` pair of attributes without patching
`binutils` build system.
We don't patch build system anymore and use multiple outputs out of
existing `binutils` build. That makes the result more maintainable: no
need to handle ever growing list of dependencied of `libbfd`. This time
new addition was `libsframe`.
To accomodate `out` / `lib` output split I had to remove `lib` -> `bin`
backreference by removing legacy lookup path for plugins.
I also did not enable `zstd` just yet as `nixpkgs` version of `zstd`
package pulls in `cmake` into bootstrap sequence.
Changes: https://lists.gnu.org/archive/html/info-gnu/2023-01/msg00003.html
FreeBSD doesn't use LLVM's cxxabi implementation, for backwards
compatibility reasons. Software expects the libcxxrt API when
building on FreeBSD. This fixes the build of
pkgsCross.x86_64-freebsd.boost.
Some other packages, for example ruby gems via buildRubyGem, use a
variable called "type" internally, which is overwritten here and
causes failures like:
failure: $gempkg path unspecified
Fix for changes in 11c3127e38.
this is intentional to support both structuredAttrs and non
In pkgs/stdenv/generic/setup.sh line 614:
for pkg in ${depsBuildBuild[@]} ${depsBuildBuildPropagated[@]}; do
^------------------^ SC2068 (error): Double quote array expansions to avoid re-splitting elements.
In pkgs/stdenv/generic/setup.sh line 521:
local varRef="$varVar[$((targetOffset - hostOffset))]"
^-- SC1087 (error): Use braces when expanding arrays, e.g. ${array[idx]} (or ${var}[.. to quiet).
exit -1 == exit 255 but we don't have a reason to use 255
In pkgs/stdenv/generic/setup.sh line 518:
(( hostOffset <= targetOffset )) || exit -1
^-- SC2242 (error): Can only exit with status 0-255. Other data should be wri
tten to stdout/stderr.
`builtins.baseNameOf` retains any string context, causing the test
derivation to incorrectly depend on `pkgs.glibc`. All we really want is
to know what the dynamicLinker is called, but we don't need it to be
present in store.
Thanks to Adam Joseph for spotting this.
we use [*] to support structuredAttrs and non
In pkgs/stdenv/generic/setup.sh line 1542:
for curPhase in ${phases[*]}; do
^----------^ SC2048 (warning): Use "${array[@]}" (with quotes) to prevent whitespace problems.
In pkgs/stdenv/generic/setup.sh line 101:
source "$hookName"
^---------^ SC1090 (warning): ShellCheck can't follow non-constant source. Use a directive to specify location.
In pkgs/stdenv/generic/setup.sh line 166:
mkdir -p "$out/nix-support"
^--^ SC2154 (warning): out is referenced but not assigned.
In pkgs/stdenv/generic/setup.sh line 407:
PATH=
^--^ SC2123 (warning): PATH is the shell search path. Use another name.
In pkgs/stdenv/generic/setup.sh line 452:
declare -a pkgBuildAccumVars=(pkgsBuildBuild pkgsBuildHost pkgsBuildTarget)
^---------------^ SC2034 (warning): pkgBuildAccumVars appears unused. Verify use (or export if used e
xternally).
because pkgBuildAccumVars is used
In pkgs/stdenv/generic/setup.sh line 235:
nameref="$* ${nameref-}"
^-----^ SC2178 (warning): Variable was used as an array but is now assigned a string.
because we theres a useArray conditional
In pkgs/stdenv/generic/setup.sh line 36:
: ${outputs:=out}
^-------------^ SC2223 (info): This default assignment may cause DoS due to globbing. Quote it.
After https://github.com/NixOS/nixpkgs/pull/209054 we started moving
libstdc++.so out of default glibc's paths. This exposed bootstrap
tools build failure as:
$ nix build --no-link -f ./pkgs/stdenv/linux/make-bootstrap-tools.nix
...
>
.../bin/bar: error while loading shared libraries: libstdc++.so.6:
cannot open shared object file: No such file or directory
Note that bootstrap itself did not break. The change only expands
handcrafted `-rpath` entries.
The stdenv bootstrap creates several wrappers around binutils, and
gives them the exact same drvName as the binutils package itself.
These wrappers cost almost nothing to create (they are just file
copies and patchelf runs, not builds), so we should distinguish them
from expensive binutils builds with a unique pname. This commit
does that.
`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>
Right now we build gettext several times during the bootstrap.
Gettext's build process is "embarrassingly serial", so avoiding
rebuilding it speeds things up considerably.
otherwise the build just fails with 'make: *** No rule to make target 'install'. Stop.'
and update buildPhase message
i don't know if the 'makefile may have been created in buildPhase' is
true but i guess it might be possible
This change allows building new gcc during bootstrap without fear of
pulling in outdated libstdc++.so after g++ switched from bootstrapTools
to freshly built g++.
Noticed when tried to add early bootstrap stage to rebuild `gcc` before
`glibc` is fully untangled from `bootstrapTools` as a failure to built
`binutils`:
ld: dwp.o: in function `__gnu_cxx::new_allocator<gold::Dwp_output_file::Contribution>::allocate(unsigned long, void const*)':
/nix/store/...-gcc-11.3.0/include/c++/11.3.0/ext/new_allocator.h:116: undefined reference to `std::__throw_bad_array_new_length()'
The change survives existing bootstrap and unblockes early `gcc` bootstrap.
Just a few comments added:
- added a few one-liners to explore which tools are rebuilt at each
stdenv iteration during bootstrap
- explicitly listed available toolchains and their sources for on each
bootstrap step: glibc, binutils, gcc, coreutils.
- added mention of static libraries linked into gcc
Co-authored-by: Adam Joseph <54836058+amjoseph-nixpkgs@users.noreply.github.com>
The documentation for `meta.sourceProvenance` in
`doc/stdenv/meta.chapter.md` says: "the `meta.sourceProvenance`
attribute should be a list containing one or more value..."
Let's update check-meta.nix to require that `meta.sourceProvenance` is
a list, as the documentation says, rather than a single element.
Adding two extra keystrokes `[` and `]` when filling out this field is
an insignificant burden for package authors, and being able to assume
that the `meta.sourceProvenance` field is always a list greatly
simplifies any code that acts on the value of this field.
Since `meta.sourceProvenance` was just merged a few hours ago now is
the easiest time to fix this: nobody is using the feature yet.
Without the change we don't propagate `enableParallelBuilding = true`
and leave most builds sequential.
Noticed on `mythtv` package which did not specify parallelism and
`config.enableParallelBuildingByDefault = true` had no effect.
Derivations not using `__structuredAttrs` should not attempt to set
environment variables from `env`.
Derivations using `__structuredAttrs` should fail if `env` is not
exportable.
Co-authored-by: Robin Gloster <mail@glob.in>
stdenv: print message if structuredAttrs is enabled
stdenv: add _append
reduces the chance of a user doing it wrong
fix nix develop issue
output hooks don't work yet in nix develop though
making $outputs be the same on non-structuredAttrs and structuredAttrs
is too much trouble.
lets instead make a function that gets the output names
reading environment file '/nix/store/2x7m69a2sm2kh0r6v0q5s9z1dh41m4xf-xz-5.2.5-env-bin'
nix: src/nix/develop.cc:299: std::string Common::makeRcScript(nix::ref<nix::Store>, const BuildEnvironment&, const Path&): Assertion `outputs != buildEnvironment.vars.end()' failed.
use a function to get all output names instead of using $outputs
copy env functionality from https://github.com/NixOS/nixpkgs/pull/76732/commits
In specific cases, combining the `checkMeta` and `checkMetaRecursively`
config options would result in `error: infinite recursion encountered`
fixes#193296
This is needed in order to mark a certain derivation containing a Nix
expression tarball to Hydra so that it is recognised as a channel.
When I first got an evaluation error due to using this meta attribute, I
was under the impression that nobody outside of Vuizvui[1] is using this
feature and that we don't have any occurrence of isHydraChannel in
Nixpkgs.
However, when working around[2] the issue I assumed that it's not
something that should be included in Nixpkgs because we're not using it
there.
It turned out that my assumption was wrong and we *do* use the attribute
in Nixpkgs, namely via releaseTools.channel, which is similar to what
we're doing in Vuizvui.
Since we already include a bunch of undocumented attributes in
metaTypes, it only makes sense to add isHydraChannel as well since it's
actually documented in the Hydra documentation[3].
[1]: https://github.com/openlab-aux/vuizvui
[2]: https://github.com/openlab-aux/vuizvui/commit/e0685e81b3fdc43a272f0
[3]: 53335323ae/doc/manual/src/jobs.md (meta-fields)
Signed-off-by: aszlig <aszlig@nix.build>
Passing `-l$NIX_BUILD_CORES` improperly limits the overall system load.
For a build machine which is configured to run `$B` builds where each
build gets `total cores / B` cores (`$C`), passing `-l $C` to make will
improperly limit the load to `$C` instead of `$B * $C`.
This effect becomes quite pronounced on machines with 80 cores, with
40 simultaneous builds and a cores limit of 2. On a machine with this
configuration, Nix will run 40 builds and make will limit the overall
system load to approximately 2. A build machine with this many cores
can happily run with a load approaching 80.
A non-solution is to oversubscribe the machine, by picking a larger
`$C`. However, there is no way to divide the number of cores in a way
which fairly subdivides the available cores when `$B` is greater than
1.
There has been exploration of passing a jobserver in to the sandbox,
or sharing a jobserver between all the builds. This is one option, but
relatively complicated and only supports make. Lots of other software
uses its own implementation of `-j` and doesn't support either `-l` or
the Make jobserver.
For the case of an interactive user machine, the user should limit
overall system load using `$B`, `$C`, and optionally systemd's
cpu/network/io limiting features.
Making this change should significantly improve the utilization of our
build farm, and improve the throughput of Hydra.
Stdenv on aarch64-darwin pulls in (bootstrap-stage4) objc4, unlike
x86_64. However derivations that otherwise depend on objc4 would use a
a different objc4 derivation on top of the final stdenv.
Because this library defines an LLVM module, having multiple instances
of it in the import path will interfere with builds.
This PR provides the Hydra-generated bootstrap tarballs for mips64el-linux-gnuabin32.
With this PR we now have the bootstrap-file for all three little-endian ABIs on mips: n64, n32, and o32. I do not currently plan to do big-endian mips unless some motivation arises; all mips chips are bi-endian and Debian has dropped big-endian support due to lack of interest.
I'll be following the script used in #151399, #168199, and #183487.
Files came from [this](https://hydra.nixos.org/build/188389586#tabs-summary) Hydra build, which used nixpkgs revision 97d9c84e1d to instantiate:
```
/nix/store/hakn8s85s9011v61r6svp5qy8x1y64fv-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabin32.drv
```
and then built:
```
/nix/store/rjgybpnf3yiqyhvl2n2lx31jf800fii2-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabin32
```
I downloaded these files from Hydra and prefetched them into the nix store with the following commands:
```
STOREPATH=rjgybpnf3yiqyhvl2n2lx31jf800fii2-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabin32
OPTIONS="--option binary-caches https://cache.nixos.org --option trusted-public-keys cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
nix store prefetch-file \
file://$(nix store add-file --name bootstrap-tools.tar.xz $(nix-store ${OPTIONS} -r /nix/store/${STOREPATH})/on-server/bootstrap-tools.tar.xz)
nix store prefetch-file --executable \
file://$(nix store add-path --name busybox $(nix-store ${OPTIONS} -r /nix/store/${STOREPATH})/on-server/busybox)
```
These commands produced the following output:
```
Downloaded 'file:///nix/store/w6zzd2fx2vhmjfcf5h5zc01m0swldpbw-bootstrap-tools.tar.xz' to '/nix/store/6w0f0mqblrghvh6yjwcb4xdqq9x50lbl-w6zzd2fx2vhmjfcf5h5zc01m0swldpbw-bootstrap-tools.tar.xz' (hash 'sha256-LWrpN6su2yNVurUyhZP34OiZyzgh7MfN13fIIbou8KI=').
Downloaded 'file:///nix/store/nqagw1kgdz1zlmqi00qfjrmwqk3g3bgd-busybox' to '/nix/store/i361xhbdhhnvg7zd637xpm63vbl80s0s-nqagw1kgdz1zlmqi00qfjrmwqk3g3bgd-busybox' (hash 'sha256-4N3G1qYA7vitjhsIW17pR6UixIuzrq4vZXa8F0/X4iI=').
```
I used the hashes from the output above to create the `fetchurl` invocation which is part of this commit.
I then started the bootstrap with the following command:
```
nix build -L -f . --arg localSystem '(import ./lib).systems.examples.mips64el-linux-gnuabin32' hello
```
As @lovesegfault requested, here are the the `sha256sum`s of all the `on-server` components for extra verification:
```
sha256sum /nix/store/${STOREPATH}/on-server/*
```
which produced the following output:
```
2d6ae937ab2edb2355bab5328593f7e0e899cb3821ecc7cdd777c821ba2ef0a2 /nix/store/rjgybpnf3yiqyhvl2n2lx31jf800fii2-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabin32/on-server/bootstrap-tools.tar.xz
01633f71135cb9ab1b5ce3ebb67e80cbf288739729bffc1350c1552f6f8df34b /nix/store/rjgybpnf3yiqyhvl2n2lx31jf800fii2-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabin32/on-server/busybox
```
inherit_errexit wasn’t available in bash 3. We have a check to show a
nice error message, but that check is after we set inherit_errexit in
setup.sh. So we can just move this to below the BASH_VERSINFO check.
gcc stopped using libelf in commit 48215350c24 ("re PR lto/46273 (Failed
to bootstrap)") around 2010, before gcc-4.6.0.
Bootstrap tools don't use it either.
This PR updates the Hydra-generated bootstrap tarballs for
powerpc64le-linux. The bootstrap-files referenced prior to this
commit will only bootstrap in a nixpkgs which has
https://github.com/NixOS/nixpkgs/pull/181802. That PR was closed in
favor of https://github.com/NixOS/nixpkgs/pull/181943, which is a
cleaner solution but which requires regenerating the bootstrap-files.
I'll be following the script established in
https://github.com/NixOS/nixpkgs/pull/151399, which I previously used
in https://github.com/NixOS/nixpkgs/pull/168199.
Files came from [this](https://hydra.nixos.org/build/186237511) Hydra build, which used nixpkgs revision ac43c44478 to instantiate:
```
/nix/store/nhjbza9vlcyhp9zxfz6lwpc3m2ghrpzj-stdenv-bootstrap-tools-powerpc64le-unknown-linux-gnu.drv
```
and then built:
```
/nix/store/fklpm7fy6cp5wz55w0gd8wakyqvzapjx-stdenv-bootstrap-tools-powerpc64le-unknown-linux-gnu
```
I downloaded these files from Hydra with the following commands:
```
STOREPATH=fklpm7fy6cp5wz55w0gd8wakyqvzapjx-stdenv-bootstrap-tools-powerpc64le-unknown-linux-gnu
OPTIONS="--option binary-caches https://cache.nixos.org --option trusted-public-keys cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
nix store add-file \
--name bootstrap-tools.tar.xz \
$(nix-store ${OPTIONS} -r /nix/store/${STOREPATH})/on-server/bootstrap-tools.tar.xz
nix store add-path \
--name busybox \
$(nix-store ${OPTIONS} -r /nix/store/${STOREPATH})/on-server/busybox
```
I then prefetched them into `/nix/store` with:
```
$ nix store prefetch-file --executable file:///nix/store/p9lz8r81zp3a4sl2qq2v4j69syjzryn2-busybox
Downloaded 'file:///nix/store/p9lz8r81zp3a4sl2qq2v4j69syjzryn2-busybox' to '/nix/store/a42qf2kf5hychcsw5sz0pvghy9vli1im-p9lz8r81zp3a4sl2qq2v4j69syjzryn2-busybox' (hash 'sha256-jtPEAsht4AUAG4MLK8xocQSfveUR4ppU1lS4bGI1VN4=').
$ nix store prefetch-file file:///nix/store/y4530zpk7ia4szf5cdi4zpyy5lpjv3iv-bootstrap-tools.tar.xz
Downloaded 'file:///nix/store/y4530zpk7ia4szf5cdi4zpyy5lpjv3iv-bootstrap-tools.tar.xz' to '/nix/store/kgzyq9q08nll28ccqjcbv8angq5hyvdp-y4530zpk7ia4szf5cdi4zpyy5lpjv3iv-bootstrap-tools.tar.xz' (hash 'sha256-MpIDnpZUK3M17qlnuoxfnK0EgxRosm3TMW1WfPZ1+jU=').
```
And started the bootstrap with the following command:
```
nix build -f . -L hello
```
As @lovesegfault requested in #151399, here are the the `sha256sum`s of all the `on-server` components for extra verification:
```
$ sha256sum /nix/store/fklpm7fy6cp5wz55w0gd8wakyqvzapjx-stdenv-bootstrap-tools-powerpc64le-unknown-linux-gnu/on-server/*
3292039e96542b7335eea967ba8c5f9cad04831468b26dd3316d567cf675fa35 /nix/store/fklpm7fy6cp5wz55w0gd8wakyqvzapjx-stdenv-bootstrap-tools-powerpc64le-unknown-linux-gnu/on-server/bootstrap-tools.tar.xz
3d078dff7b4087d82442937667c91dace3321493aae4d3a4160d046b7eabcc2c /nix/store/fklpm7fy6cp5wz55w0gd8wakyqvzapjx-stdenv-bootstrap-tools-powerpc64le-unknown-linux-gnu/on-server/busybox
```
This is a change for `powerpc-linux` but that is ancient and I don't
think it matters. The impure bootstrap that was previously assigned to
it has probably bitrotted anyways.
Before the change an attempt to use `gnumake.override { guileSupport = true; }`
caused recursion in bootstrap stages as guileSupport pulls in guile and it's
dependencies.
To restore the bootstrap the change unconditionally sets
`guileSupport = false;` for `gnumake`.
Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
the motivation for this is to simplify stdenv and ease the job of
reviewers due to them needing to tell contributors about the defacto
rule that mesonFlags should be a list of strings
This PR adds Hydra-generated bootstrap tarballs for mips64el-linux. I'll be following the script established in https://github.com/NixOS/nixpkgs/pull/151399, which I previously used in https://github.com/NixOS/nixpkgs/pull/168199.
Files came from [this](https://hydra.nixos.org/build/182757245) Hydra build, which used nixpkgs revision ef3fe254f3 to instantiate:
```
/nix/store/a2bvv663wjnyhq8m7v84aspsd3sgf9h6-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64.drv
```
and then built:
```
/nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64
```
I downloaded these files from Hydra with the following commands:
```
STOREPATH=aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64
OPTIONS="--option binary-caches https://cache.nixos.org"
nix store add-file \
--name bootstrap-tools.tar.xz \
$(nix-store ${OPTIONS} -r /nix/store/${STOREPATH})/on-server/bootstrap-tools.tar.xz
nix store add-path \
--name busybox \
$(nix-store ${OPTIONS} -r /nix/store/${STOREPATH})/on-server/busybox
```
I then prefetched them into `/nix/store` with:
```
$ nix store prefetch-file --executable file:///nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64/on-server/busybox
Downloaded 'file:///nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64/on-server/busybox' to '/nix/store/ai30ss23914syz6j8m95arkwffbbx44k-busybox' (hash 'sha256-sTE58ofjqAqX3Xtq1g9wDxzIe6Vo//GHbicfqJoivDI=').
$ nix store prefetch-file file:///nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64/on-server/bootstrap-tools.tar.xz
Downloaded 'file:///nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64/on-server/bootstrap-tools.tar.xz' to '/nix/store/nr6zjrbwbxcxs6brf042zsyqllwbwj9v-bootstrap-tools.tar.xz' (hash 'sha256-tTgjeXpd2YgnfP4JvRuO0bXd2j8GqzBcd57JI3wH9x0=').
```
And started the bootstrap with the following command (the `--arg localSystem` is needed because #161159 has not merged):
```
nix build -f . -L hello --arg localSystem '(import ./lib).systems.examples.mips64el-linux-gnuabi64'
```
As @lovesegfault requested in #151399, here are the the `sha256sum`s of all the `on-server` components for extra verification:
```
$ sha256sum /nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64/on-server/*
b53823797a5dd988277cfe09bd1b8ed1b5ddda3f06ab305c779ec9237c07f71d /nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64/on-server/bootstrap-tools.tar.xz
598e05abb69b2c1a0db46585cd2131212077c0937ce2a665daf3811f059ae767 /nix/store/aw3dmsrh22831l83vi3q9apg9qi3x8ms-stdenv-bootstrap-tools-mips64el-unknown-linux-gnuabi64/on-server/busybox
```
the motivation for this is to simplify stdenv and ease the job of
reviewers due to them needing to tell contributors about the defacto
rule that cmakeFlags should be a list of strings
Closes#178625
The `busybox` version of `mktemp` requires exactly six `X` characters
in the argument to `mktemp`, unlike the `coreutils` version of `mktemp`.
Let's accomodate packages, like `epson-escpr2`, which fool `setup.sh`
into using the `busybox` version instead of the `stdenv` version.