This was originally added in #4770 to support structured attrs in
`nix-shell` & `nix develop`: the issue was that it was somewhat awkward
to just write those files into a project directory, especially since
it'd break in case of multiple `nix-shell` invocations from the same
directory. Now the files are written to another, temporary
location when using `nix-shell`/`nix develop` and the correct path is
referenced by NIX_ATTRS_*_FILE.
In `nixpkgs`, it's now common to use these environment variables,
however we still fall back to checking to `.attrs.sh` & `.attrs.json`
since the minimum Nix version we support is 2.3.17[1] which doesn't have
this change.
This however makes implementing structured attrs support more
complicated than needed[2] and in fact we have a few places where the
check for `.attrs.sh`/`.attrs.json` isn't made, so these only break with
Nix 2.3[3].
The idea is now to
* get this into 2.3.18
* bump minver once again to 2.3.18 in nixpkgs
* remove all occurrences of `.attrs.sh`/`.attrs.json` from nixpkgs.
[1] f4bd97b8fa/lib/minver.nix
[2] https://github.com/NixOS/nixpkgs/pull/357053/files#diff-791a01ef89c157eb74d9c87ab8cbc3b81e2cf082cab70b8fec3472cd75ce860dR3-R5
[3] https://github.com/NixOS/nixpkgs/pull/357053#discussion_r1857362490
It is possible to exfiltrate a file descriptor out of the build sandbox
of FODs, and use it to modify the store path after it has been
registered.
To avoid that issue, don't register the output of the build, but a copy
of it (that will be free of any leaked file descriptor).
If there were many top-level goals (which are not destroyed until the
very end), commands like
$ nix copy --to 'ssh://localhost?remote-store=/tmp/nix' \
/run/current-system --no-check-sigs --substitute-on-destination
could fail with "Too many open files". So now we do some explicit
cleanup from amDone(). It would be cleaner to separate goals from
their temporary internal state, but that would be a bigger refactor.
Backport 8a29052cb2
Before this commit, the dns lookup in preloadNSS would still go through
nscd. This did not have the effect of loading the nss_dns.so as expected
(nss_dns.so being out of reach from within the sandbox).
Should LOCALDOMAIN environment variable be defined, nss will completely
avoid nscd and will do its dns resolution on its own.
By temporarly setting LOCALDOMAIN variable before calling in NSS, we can
force NSS to load the shared libraries as expected.
Signed-off-by: Arthur Gautier <baloo@superbaloo.net>
Starting in macOS 11, the on-disk dylib bundles are no longer available,
but nixpkgs needs to be able to keep compatibility with older versions
that require `/usr/lib/libSystem.B.dylib` in `__impureHostDeps`. Allow
it to keep backwards compatibility with these versions by marking these
dependencies as optional.
Fixes#4658.
(cherry picked from commit c4355a52fa)
Signed-off-by: Domen Kožar <domen@dev.si>
If we're a single-user installation of Nix, then we won't have root
superpowers to just ignore the permission bits. This means that we'll
need permission on the directory (if it's a directory) that we're moving
in order to move it with rename, because it must update the ".."
directory entry.
Fixes#4295.
This is already working in master, thanks to
e913a2989f (and followup cleanups).
Observed on Centos 7 when user namespaces are disabled:
DerivationGoal::startBuilder() throws an exception, ~DerivationGoal()
waits for the child process to exit, but the child process hangs
forever in drainFD(userNamespaceSync.readSide.get()) in
DerivationGoal::runChild(). Not sure why the SIGKILL doesn't get
through.
Issue #4092.
(cherry picked from commit d761485010)
Otherwise `chmod .`'ing the build directory doesn't work anymore, which
is done in nixpkgs if sourceRoot is set to '.'.
(cherry picked from commit f8dbde0813)
The tmpDirInSandbox is different when in sandboxed vs. non-sandboxed.
Since we don’t know ahead of time here whether sandboxing is enabled,
we need to reset all of the env vars we’ve set previously. This fixes
the issue encountered in https://github.com/NixOS/nixpkgs/issues/70856.
(cherry picked from commit 499b038875)
POSIX file locks are essentially incompatible with multithreading. BSD
locks have much saner semantics. We need this now that there can be
multiple concurrent LocalStore::buildPaths() invocations.
Passing `--post-build-hook /foo/bar` to a nix-* command will cause
`/foo/bar` to be executed after each build with the following
environment variables set:
DRV_PATH=/nix/store/drv-that-has-been-built.drv
OUT_PATHS=/nix/store/...build /nix/store/...build-bin /nix/store/...build-dev
This can be useful in particular to upload all the builded artifacts to
the cache (including the ones that don't appear in the runtime closure
of the final derivation or are built because of IFD).
This new feature prints the stderr/stdout output to the `nix-build`
and `nix build` client, and the output is printed in a Nix 2
compatible format:
[nix]$ ./inst/bin/nix-build ./test.nix
these derivations will be built:
/nix/store/ishzj9ni17xq4hgrjvlyjkfvm00b0ch9-my-example-derivation.drv
building '/nix/store/ishzj9ni17xq4hgrjvlyjkfvm00b0ch9-my-example-derivation.drv'...
hello!
bye!
running post-build-hook '/home/grahamc/projects/github.com/NixOS/nix/post-hook.sh'...
post-build-hook: + sleep 1
post-build-hook: + echo 'Signing paths' /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
post-build-hook: Signing paths /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
post-build-hook: + sleep 1
post-build-hook: + echo 'Uploading paths' /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
post-build-hook: Uploading paths /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
post-build-hook: + sleep 1
post-build-hook: + printf 'very important stuff'
/nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
[nix-shell:~/projects/github.com/NixOS/nix]$ ./inst/bin/nix build -L -f ./test.nix
my-example-derivation> hello!
my-example-derivation> bye!
my-example-derivation (post)> + sleep 1
my-example-derivation (post)> + echo 'Signing paths' /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
my-example-derivation (post)> Signing paths /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
my-example-derivation (post)> + sleep 1
my-example-derivation (post)> + echo 'Uploading paths' /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
my-example-derivation (post)> Uploading paths /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
my-example-derivation (post)> + sleep 1
my-example-derivation (post)> + printf 'very important stuff'
[1 built, 0.0 MiB DL]
Co-authored-by: Graham Christensen <graham@grahamc.com>
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
startProcess does not appear to send the exit code to the helper
correctly. Not sure why this is, but it is probably safe to just
fallback on all sandbox errors.
When sandbox-fallback = true (the default), the Nix builder will fall
back to disabled sandbox mode when the kernel doesn’t allow users to
set it up. This prevents hard errors from occuring in tricky places,
especially the initial installer. To restore the previous behavior,
users can set:
sandbox-fallback = false
in their /etc/nix/nix.conf configuration.
Some kernels disable "unpriveleged user namespaces". This is
unfortunate, but we can still use mount namespaces. Anyway, since each
builder has its own nixbld user, we already have most of the benefits
of user namespaces.
If multiple builds with fail with different errors it will be reflected
in the status code.
eg.
103 => timeout + hash mismatch
105 => timeout + check mismatch
106 => hash mismatch + check mismatch
107 => timeout + hash mismatch + check mismatch
The default nsswitch.conf(5) file in most distros can handle many
different things including host name, user names, groups, etc. In Nix,
we want to limit the amount of impurities that come from these things.
As a result, we should only allow nss to be used for gethostbyname(3)
and getservent(3).
/cc @Ericson2314
This allows many programs (e.g. gcc, clang, cmake) to print colorized
log output (assuming $TERM is set to a value like "xterm").
There are other ways to get colors, in particular setting
CLICOLOR_FORCE, but they're less widely supported and can break
programs that parse tool output.
The value of useChroot is not set yet in the constructor, resulting in
hash rewriting being enabled in certain cases where it should not be.
Fixes#2801
To determine which seccomp filters to install, we were incorrectly
using settings.thisSystem, which doesn't denote the actual system when
--system is used.
Fixes#2791.
This reverts commit a0ef21262f. This
doesn't work in 'nix run' and nix-shell because setns() fails in
multithreaded programs, and Boehm GC mark threads are uncancellable.
Fixes#2646.
Use the same output ordering and format everywhere.
This is such a common issue that we trade the single-line error message for
more readability.
Old message:
```
fixed-output derivation produced path '/nix/store/d4nw9x2sy9q3r32f3g5l5h1k833c01vq-example.com' with sha256 hash '08y4734bm2zahw75b16bcmcg587vvyvh0n11gwiyir70divwp1rm' instead of the expected hash '1xzwnipjd54wl8g93vpw6hxnpmdabq0wqywriiwmh7x8k0lvpq5m'
```
New message:
```
hash mismatch in fixed-output derivation '/nix/store/d4nw9x2sy9q3r32f3g5l5h1k833c01vq-example.com':
wanted: sha256:1xzwnipjd54wl8g93vpw6hxnpmdabq0wqywriiwmh7x8k0lvpq5m
got: sha256:08y4734bm2zahw75b16bcmcg587vvyvh0n11gwiyir70divwp1rm
```
