With Linux kernel >=6.6 & glibc 2.39 a `fchmodat2(2)` is available that
isn't filtered away by the libseccomp sandbox.
Being able to use this to bypass that restriction has surprising results
for some builds such as lxc[1]:
> With kernel ≥6.6 and glibc 2.39, lxc's install phase uses fchmodat2,
> which slips through 9b88e52846/src/libstore/build/local-derivation-goal.cc (L1650-L1663).
> The fixupPhase then uses fchmodat, which fails.
> With older kernel or glibc, setting the suid bit fails in the
> install phase, which is not treated as fatal, and then the
> fixup phase does not try to set it again.
Please note that there are still ways to bypass this sandbox[2] and this is
mostly a fix for the breaking builds.
This change works by creating a syscall filter for the `fchmodat2`
syscall (number 452 on most systems). The problem is that glibc 2.39
is needed to have the correct syscall number available via
`__NR_fchmodat2` / `__SNR_fchmodat2`, but this flake is still on
nixpkgs 23.11. To have this change everywhere and not dependent on the
glibc this package is built against, I added a header
"fchmodat2-compat.hh" that sets the syscall number based on the
architecture. On most platforms its 452 according to glibc with a few
exceptions:
$ rg --pcre2 'define __NR_fchmodat2 (?!452)'
sysdeps/unix/sysv/linux/x86_64/x32/arch-syscall.h
58:#define __NR_fchmodat2 1073742276
sysdeps/unix/sysv/linux/mips/mips64/n32/arch-syscall.h
67:#define __NR_fchmodat2 6452
sysdeps/unix/sysv/linux/mips/mips64/n64/arch-syscall.h
62:#define __NR_fchmodat2 5452
sysdeps/unix/sysv/linux/mips/mips32/arch-syscall.h
70:#define __NR_fchmodat2 4452
sysdeps/unix/sysv/linux/alpha/arch-syscall.h
59:#define __NR_fchmodat2 562
I added a small regression-test to the setuid integration-test that
attempts to set the suid bit on a file using the fchmodat2 syscall.
I confirmed that the test fails without the change in
local-derivation-goal.
Additionally, we require libseccomp 2.5.5 or greater now: as it turns
out, libseccomp maintains an internal syscall table and
validates each rule against it. This means that when using libseccomp
2.5.4 or older, one may pass `452` as syscall number against it, but
since it doesn't exist in the internal structure, `libseccomp` will refuse
to create a filter for that. This happens with nixpkgs-23.11, i.e. on
stable NixOS and when building Lix against the project's flake.
To work around that
* a backport of libseccomp 2.5.5 on upstream nixpkgs has been
scheduled[3].
* the package now uses libseccomp 2.5.5 on its own already. This is to
provide a quick fix since the correct fix for 23.11 is still a staging cycle
away.
We still need the compat header though since `SCMP_SYS(fchmodat2)`
internally transforms this into `__SNR_fchmodat2` which points to
`__NR_fchmodat2` from glibc 2.39, so it wouldn't build on glibc 2.38.
The updated syscall table from libseccomp 2.5.5 is NOT used for that
step, but used later, so we need both, our compat header and their
syscall table 🤷
Relevant PRs in CppNix:
* https://github.com/NixOS/nix/pull/10591
* https://github.com/NixOS/nix/pull/10501
[1] https://github.com/NixOS/nixpkgs/issues/300635#issuecomment-2031073804
[2] https://github.com/NixOS/nixpkgs/issues/300635#issuecomment-2030844251
[3] https://github.com/NixOS/nixpkgs/pull/306070
(cherry picked from commit ba6804518772e6afb403dd55478365d4b863c854)
Change-Id: I6921ab5a363188c6bff617750d00bb517276b7fe
This commit makes Meson the default buildsystem for Lix.
The Make buildsystem is now deprecated and will be removed soon, but has
not yet, which will be done in a later commit when all seems good. The
mesonBuild jobs have been removed, and have not been replaced with
equivalent jobs to ensure the Make buildsystem still works.
The full, new commands in a development shell are:
$ meson setup ./build "--prefix=$out" $mesonFlags
(A simple `meson setup ./build` will also build, but will do a different
thing, not having the settings from package.nix applied.)
$ meson compile -C build
$ meson test -C build --suite=check
$ meson install -C build
$ meson test -C build --suite=installcheck
(Check and installcheck may both be done after install, allowing you to
omit the --suite argument entirely, but this is the order package.nix
runs them in.)
If tests fail and Meson helpfully has no output for why, use the
`--print-error-logs` option to `meson test`. Why this is not the default
I cannot explain.
If you change a setting in the buildsystem, most cases will
automatically regenerate the Meson configuration, but some cases, like
trying to build a specific target whose name is new to the buildsystem
(e.g. `meson compile -C build src/libmelt/libmelt.dylib`, when
`libmelt.dylib` did not exist as a target the last time the buildsystem
was generated), then you can reconfigure using new settings but
existing options, and only recompiling stuff affected by the changes:
$ meson setup --reconfigure build
Note that changes to the default values in `meson.options` or in the
`default_options :` argument to project() are NOT propagated with
`--reconfigure`.
If you want a totally clean build, you can use:
$ meson setup --wipe build
That will work regardless of if `./build` exists or not.
Specific, named targets may be addressed in
`meson build -C build <target>` with the "target ID" if there is one,
which is the first string argument passed to target functions that
have one, and unrelated to the variable name, e.g.:
libexpr_dylib = library('nixexpr', …)
can be addressed with:
$ meson compile -C build nixexpr
All targets may be addressed as their output, relative to the build
directory, e.g.:
$ meson compile -C build src/libexpr/libnixexpr.so
But Meson does not consider intermediate files like object files
targets. To build a specific object file, use Ninja directly and
specify the output file relative to the build directory:
$ ninja -C build src/libexpr/libnixexpr.so.p/nixexpr.cc.o
To inspect the canonical source of truth on what the state of the
buildsystem configuration is, use:
$ meson introspect
Have fun!
Change-Id: Ia3e7b1e6fae26daf3162e655b4ded611a5cd57ad
This commit adds the capability for building the Doxygen internal API
docs in the Meson buildsystem, and also makes doing so the default for
the internal-api-docs hydra job. Aside from the /nix-support directory,
which differed only by the hash part of a store path, the outputs of
hydraJobs.internal-api-docs before and after this commit were
bit-for-bit identical on my machine.
Change-Id: I98f0017891c25b06866c15f7652fe74f706ec8e1
this was previously used because the macOS docs build would otherwise
pull files out of the host nix store. or something. not sure about it
Change-Id: I76b51eac1ebc5de5f00e2e4be086dd8db3eeb8e6
manpages can be rendered using the markdown output of mdbook, the rest
of the manual can generated out of the main doc/manual source tree. we
still use lowdown to actually render manpages instead of eg mdbook-man
because lowdown does generate reasonably good manpages (though that is
also somewhat debatable, but they're a lot better than mdbook-man).
doing this not only lets us drastically simplify the lowdown pipeline,
but also remove all custom {{#include}} handling since now mdbook does
all of it, even for the manpage builds. even the lowdown wrapper isn't
entirely necessary because lowdown can take all wrapper arguments with
command line flags rather than bits of input file content.
This also implements running mdbook in Meson, in order to generate the
manpages. The mdbook outputs are also installed in the usual location.
Co-authored-by: Qyriad <qyriad@qyriad.me>
Change-Id: I60193f9fd0f15d48872f071af35855cda2a0f40b
Previously, errors while printing values in `nix repl` would be printed
in `«error: ...»` brackets rather than displayed normally:
```
nix-repl> legacyPackages.aarch64-darwin.pythonPackages.APScheduler
«error: Package ‘python-2.7.18.7’ in /nix/store/6s0m1qc31zw3l3kq0q4wd5cp3lqpkq0q-source/pkgs/development/interpreters/python/cpython/2.7/default.nix:335 is marked as insecure, refusing to evaluate.»
```
Now, errors will be displayed normally if they're emitted at the
top-level of an expression:
```
nix-repl> legacyPackages.aarch64-darwin.pythonPackages.APScheduler
error:
… in the condition of the assert statement
at /nix/store/6s0m1qc31zw3l3kq0q4wd5cp3lqpkq0q-source/lib/customisation.nix:268:17:
267| in commonAttrs // {
268| drvPath = assert condition; drv.drvPath;
| ^
269| outPath = assert condition; drv.outPath;
… in the left operand of the OR (||) operator
at /nix/store/6s0m1qc31zw3l3kq0q4wd5cp3lqpkq0q-source/pkgs/development/interpreters/python/passthrufun.nix:28:45:
27| if lib.isDerivation value then
28| lib.extendDerivation (valid value || throw "${name} should use `buildPythonPackage` or `toPythonModule` if it is to be part of the Python packages set.") {} value
| ^
29| else
(stack trace truncated; use '--show-trace' to show the full trace)
error: Package ‘python-2.7.18.7’ in /nix/store/6s0m1qc31zw3l3kq0q4wd5cp3lqpkq0q-source/pkgs/development/interpreters/python/cpython/2.7/default.nix:335 is marked as insecure, refusing to evaluate.
```
Errors emitted in nested structures (like e.g. when printing `nixpkgs`)
will still be printed in brackets.
Change-Id: I25aeddf08c017582718cb9772a677bf51b9fc2ad
this isn't strictly necessary, but it'll make it a lot easier to put the
generated files used by the autoconf build system in this directory too.
doing this now already will make the meson transition a lot easier later
Change-Id: I5fb39eade2ff88b6093c9ee436c9e8db793e9448
this would make meson build compatibility unnecessarily hard and
the cli does not change often enough to justify this complexity.
Change-Id: I17b1870cdf8538feeaa01a9945db97af2175a642
not sure why this was done the way it was considering that includes are
a feature the doc toolchain had previously. let's just always have some
kind of entry for the upcoming release in the dev manual builds even if
that means having a completely empty release notes chapter.
the release notes generation script isn't entirely functional right now
due to pre-commit hooks, but it's good enough for time being. we need a
better release process for notes anyway.
Change-Id: Ifda6912cf5233db013f72a30247a62d6f22b1565
Change-Id: I9eb347ec4aabc5be2b816ff0fd3e4be45f93b934
mdbook already does include processing of its own, and the custom
processing code has always admitted as much. we don't need it for
the mdbook build at this point if we run our preprocessors in the
right order, and maybe we can even have mdbook to return complete
pages to us that we only have to pass to lowdown without any more
preprocessing of our own.
Change-Id: Icd978acbc3b1e215fee8f062c53ab2cb2a222ab1
for some reason these three were anchors, not links, but had they been
links they wouldn't've worked because they're not defined anywhere but
here. in the print version of the manual they're duplicated many times
over (creating id collisions), so we should better remove them anyway.
Change-Id: I8988a7c32c812dee0f0b6d4953faa7cd1255228d
Adds a `repl-overlays` option, which specifies files that can overlay
and modify the top-level bindings in `nix repl`. For example, with the
following contents in `~/.config/nix/repl.nix`:
info: final: prev: let
optionalAttrs = predicate: attrs:
if predicate
then attrs
else {};
in
optionalAttrs (prev ? legacyPackages && prev.legacyPackages ? ${info.currentSystem})
{
pkgs = prev.legacyPackages.${info.currentSystem};
}
We can run `nix repl` and use `pkgs` to refer to `legacyPackages.${currentSystem}`:
$ nix repl --repl-overlays ~/.config/nix/repl.nix nixpkgs
Lix 2.90.0
Type :? for help.
Loading installable 'flake:nixpkgs#'...
Added 5 variables.
Loading 'repl-overlays'...
Added 6 variables.
nix-repl> pkgs.bash
«derivation /nix/store/g08b5vkwwh0j8ic9rkmd8mpj878rk62z-bash-5.2p26.drv»
Change-Id: Ic12e0f2f210b2f46e920c33088dfe1083f42391a
`nix eval --write-to` refuses to write to a directory that exists at
all, so now we generate in a temporary directory, and copy the generated
tree to the build directory. This is equivalent to what the Make
buildsystem did, actually, but hopefully more robust.
Future work: documenting the doc generation architecture in the
top-level meson.build outline comment.
Change-Id: Ic3eb6d26e3cc249a1c042fd3ced22d637ac66a69
This is terrible UX, and frankly an eval failure should be a cache
invalidation anyway.
This removes the CachedEvalError type entirely.
Fixes#223.
Change-Id: I91f8003eabd0ea45003024e96d1de3c7ae8e49d8
We're not entirely clear on why the links preprocessor has to be done
*before* rather than after, but we assume it is probably that as a
builtin preprocessor it does some processing on the raw book source,
and not just the JSON data.
Also a real use for Python pattern matching? I know I was surprised too.
Change-Id: Ibe8b59e7b5bd5f357a655d8b4c5f0b0f58a67d6b
This reverts commit 70954233743a233744787103d3211237a28ddbca.
This seems to have broken running ninja on warm build directories, which
is not what we want. Reverted until we figure out something better
Change-Id: I9623ae078917e7c59a930bf8044a216501d4bb20
This puts the generated files where they are for the make system.
This is in preparation for further meson-mdbook stuff.
Change-Id: I934df6854a80af5ccf381cf1da0bda0187a8bcfc
For a long time `nix repl` has supported displaying documentation set on
builtins, however, it has long been convention to use Markdown comments
on Nix functions themselves for documentation. This exposes that
information to `nix repl` users in a nice and formatted way.
NixOS/rfcs#145 doc-comments are primarily what this feature is intended
to consume, however, support for lambda documentation in the repl is
experimental. We do our best effort to support the RFC here.
These changes are based on [the nix-doc library](https://github.com/lf-/nix-doc) and
are licensed under the terms described in the relevant source files.
Change-Id: Ic6fe947d39a22540705d890737e336c4720b0a22
this notably does *not* install the `nix3-manpages` manpage the old
system generated, mostly because that page was empty and just a bug
with a coat of documentation paint.
Change-Id: I7a4248a72e7bb5e0cc925a6311a33b6b72589569
we'll want to use these for the meson builds, and probably eventually
rewrite them in something that isn't plain shell. diffoscope confirms
that out/share and doc/share are equal before and after these changes
Change-Id: I49aa418fc8615cad86d67328e08c28a7405ec952
The big ones here are `trim-trailing-whitespace` and `end-of-file-fixer`
(which makes sure that every file ends with exactly one newline
character).
Change-Id: Idca73b640883188f068f9903e013cf0d82aa1123
We don't apply any patches to it, and vendoring it locks users into
bugs (it hasn't been updated since its introduction in late 2021).
Closes #164
Change-Id: Ied071c841fc30b0dfb575151afd1e7f66970fdb9
I didn't enable this by default for clang due to making the build time
10% worse or so. Unfortunate, but tbh devs for whom 10% of build time is
not *that* bad should probably simply enable this.
Change-Id: I8d1e5b6f3f76c649a4e2f115f534f7f97cee46e6
hacking changelog-d to support not just github but also forgejo and
gerrit is a lot more complicated than it's worth, even moreso since
the entire thing can just as well be done with ~60 lines of python.
this new script is also much cheaper to instantiate (being python),
so having it enabled in all shells is far less of a hassle.
we've also adjusted existing release notes that referenced a gerrit
cl to auto-link to the cl in question, making the diff a bit bigger
closes #176
Change-Id: I8ba7dd0070aad9ba4474401731215fcf5d9d2130
previously we reported the error at the beginning of the binding
block (for plain inherits) or the beginning of the attr list (for
inherit-from), effectively hiding where exactly the error happened.
this also carries over to runtime positions of attributes in sets as
reported by unsafeGetAttrPos. we're not worried about this changing
observable eval behavior because it *is* marked unsafe, and the new
behavior is much more useful.
(cherry picked from commit 1edd6fada53553b89847ac3981ac28025857ca02)
Change-Id: I2f50eb9f3dc3977db4eb3e3da96f1cb37ccd5174
we already normalize attr order to lexicographic, doing the same for
formals makes sense. doubly so because the order of formals would
otherwise depend on the context of the expression, which is not quite as
useful as one might expect.
(cherry picked from commit 4147ecfb1c51f3fe3b4adcbd4e753fd487dab645)
Change-Id: I3fd0dbdef3ac7447a3a03ff20bb514a0d0f23fb1
diagnose attr duplication at the path the duplication was detected, not
at the path the current attribute wanted to place. doing the latter is
only correct if a leaf attribute was duplicated, not if an attrpath was
set to a non-attrset in one binding and a (potentially implied) attrset
in another binding.
fixes#124
Change-Id: Ic4aa9cc12a9874d4e7897c6f64408f10aa36fc82
desugaring inherit-from to syntactic duplication of the source expr also
duplicates side effects of the source expr (such as trace calls) and
expensive computations (such as derivationStrict).
(cherry picked from commit cefd0302b55b3360dbca59cfcb4bf6a750d6cdcf)
Change-Id: Iff519f991adef2e51683ba2c552d37a3df7a179e
Enter debugger on `builtins.trace` with an option
(cherry picked from commit 774e7ca5847ebc392eac2a124a8f12b24da4f65a)
Change-Id: If01e2110b3a128e639b05143227e365227d149f1
Enter debugger more reliably in `let` expressions and function calls
(cherry picked from commit c4ed92fa6f836d3d8eb354a48c37a2f9eeecc3aa)
Change-Id: I16d0cad7e898feecd2399723b92ba8df67222fb4
Print the value in `error: cannot coerce` messages
(cherry picked from commit 5b7bfd2d6b89d7dd5f54c1ca6c8072358d31a84e)
===
test taken from 6e8d5983143ae576e3f4b1d2954a5267f2943a49; it was added
previously (and not backported because its pr was a mostly-revert), but
it's useful to have around.
Change-Id: Icbd14b55e3610ce7b774667bf14b82e6dc717982
Print the value in `value is X while a Y is expected` error
(cherry picked from commit 5f72a97092da6af28a7d2b2a50d74e9d34fae7e1)
Change-Id: Idb4bc903ae59a0f5b6fb3b1da4d47970fe0a6efe
Maximilian Bosch
Qyriad
eldritch horrors
Rebecca Turner
jade
Lunaphied
Winter Cute