Otherwise, when running as root and user namespaces are enabled,
opening the slave fails with EPERM.
Fixes "opening pseudoterminal slave: Permission denied" followed by a
hang (https://hydra.nixos.org/build/213104244), and "error: getting
sandbox mount namespace: No such file or directory" (#8072), which
happens when the child fails very quickly and consequently reading
/proc/<child>/ns fails.
If we conditionally "declare" the argument, as we did before, based upon
weather the feature is enabled, commands like
nix --experimental-features=foo ... --thing-gated-on-foo
won't work, because the experimental feature isn't enabled until *after*
we start parsing.
Instead, allow arguments to also be associated with experimental
features (just as we did for builtins and settings), and then the
command line parser will filter out the experimental ones.
Since the effects of arguments (handler functions) are performed right
away, we get the required behavior: earlier arguments can enable later
arguments enabled!
There is just one catch: we want to keep non-positional
flags...non-positional. So if
nix --experimental-features=foo ... --thing-gated-on-foo
works, then
nix --thing-gated-on-foo --experimental-features=foo ...
should also work.
This is not my favorite long-term solution, but for now this is
implemented by delaying the requirement of needed experimental features
until *after* all the arguments have been parsed.
We hide them in various ways if the experimental feature isn't enabled.
To do this, we had to move the experimental features list out of
libnixstore, because the setting machinary itself depends on it. To do
that, we made a new `ExperimentalFeatureSettings`.
Already, we had classes like `BuiltPathsCommand` and `StorePathsCommand`
which provided alternative `run` virtual functions providing the
implementation with more arguments. This was a very nice and easy way to
make writing command; just fill in the virtual functions and it is
fairly clear what to do.
However, exception to this pattern were `Installable{,s}Command`. These
two classes instead just had a field where the installables would be
stored, and various side-effecting `prepare` and `load` machinery too
fill them in. Command would wish out those fields.
This isn't so clear to use.
What this commit does is make those command classes like the others,
with richer `run` functions.
Not only does this restore the pattern making commands easier to write,
it has a number of other benefits:
- `prepare` and `load` are gone entirely! One command just hands just
hands off to the next.
- `useDefaultInstallables` because `defaultInstallables`. This takes
over `prepare` for the one case that needs it, and provides enough
flexiblity to handle `nix repl`'s idiosyncratic migration.
- We can use `ref` instead of `std::shared_ptr`. The former must be
initialized (so it is like Rust's `Box` rather than `Option<Box>`,
This expresses the invariant that the installable are in fact
initialized much better.
This is possible because since we just have local variables not
fields, we can stop worrying about the not-yet-initialized case.
- Fewer lines of code! (Finally I have a large refactor that makes the
number go down not up...)
- `nix repl` is now implemented in a clearer way.
The last item deserves further mention. `nix repl` is not like the other
installable commands because instead working from once-loaded
installables, it needs to be able to load them again and again.
To properly support this, we make a new superclass
`RawInstallablesCommand`. This class has the argument parsing and
completion logic, but does *not* hand off parsed installables but
instead just the raw string arguments.
This is exactly what `nix repl` needs, and allows us to instead of
having the logic awkwardly split between `prepare`,
`useDefaultInstallables,` and `load`, have everything right next to each
other. I think this will enable future simplifications of that argument
defaulting logic, but I am saving those for a future PR --- best to keep
code motion and more complicated boolean expression rewriting separate
steps.
The "diagnostic ignored `-Woverloaded-virtual`" pragma helps because C++
doesn't like our many `run` methods. In our case, we don't mind the
shadowing it all --- it is *intentional* that the derived class only
provides a `run` method, and doesn't call any of the overridden `run`
methods.
Helps with https://github.com/NixOS/rfcs/pull/134
We make sure the env var paths are actually set (ie. not "") before
sending them to the canonicalization function. If we forget to do so,
the user will end up facing a puzzled failed assertion internal error.
We issue a non-failing warning as a stop-gap measure. We could want to
revisit this to issue a detailed failing error message in the future.
Descriptions for commandline flags may not include newlines and should
be rather short for display in a shell. Truncate the description string
of a flag on '\n' or '.' to and add an ellipsis if needed.
XDG Base Directory is a standard for locations for storing various
files. Nix has a few files which seem to fit in the standard, but
currently use a custom location directly in the user's ~, polluting
it:
- ~/.nix-profile
- ~/.nix-defexpr
- ~/.nix-channels
This commit adds a config option (use-xdg-base-directories) to follow
the XDG spec and instead use the following locations:
- $XDG_STATE_HOME/nix/profile
- $XDG_STATE_HOME/nix/defexpr
- $XDG_STATE_HOME/nix/channels
If $XDG_STATE_HOME is not set, it is assumed to be ~/.local/state.
Co-authored-by: Théophane Hufschmitt <7226587+thufschmitt@users.noreply.github.com>
Co-authored-by: Tim Fenney <kodekata@gmail.com>
Co-authored-by: pasqui23 <pasqui23@users.noreply.github.com>
Co-authored-by: Artturin <Artturin@artturin.com>
Co-authored-by: John Ericson <Ericson2314@Yahoo.com>
In unprivileged podman containers, /proc is not fully visible (there
are other filesystems mounted on subdirectories of /proc). Therefore
we can't mount a new /proc in the sandbox that matches the PID
namespace of the sandbox. So this commit automatically disables
sandboxing if /proc is not fully visible.
This didn't work because sandboxing doesn't work in Docker. However,
the sandboxing check is done lazily - after clone(CLONE_NEWNS) fails,
we retry with sandboxing disabled. But at that point, we've already
done UID allocation under the assumption that user namespaces are
enabled.
So let's get rid of the "goto fallback" logic and just detect early
whether user / mount namespaces are enabled.
This commit also gets rid of a compatibility hack for some ancient
Linux kernels (<2.13).
clangStdenv compiles with a single warning:
```
warning: destructor called on non-final 'nix::PosAdapter' that has virtual functions but non-virtual destructor [-Wdelete-non-abstract-non-virtual-dtor]
```
This fixes the warning by making the destructor of PosAdapter virtual,
deffering to the correct destructor from the concrete child classes.
This has no impact in the end, as none of these classes have specific
destructors.
Technicaly, it may be faster not to have this indirection, but as per
the warning, there is only one place where we have to delete abstract
PosAdapter values.
Not worth bikesheding I guess.
Rather than using `/nix/var/nix/{profiles,gcroots}/per-user/`, put the user
profiles and gcroots under `$XDG_DATA_DIR/nix/{profiles,gcroots}`.
This means that the daemon no longer needs to manage these paths itself
(they are fully handled client-side). In particular, it doesn’t have to
`chown` them anymore (removing one need for root).
This does change the layout of the gc-roots created by nix-env, and is
likely to break some stuff, so I’m not sure how to properly handle that.
It appears that on current macOS versions, our use of poll() to detect
client disconnects no longer works. As a workaround, poll() for
POLLRDNORM, since this *will* wake up when the client has
disconnected. The downside is that it also wakes up when input is
available. So just sleep for a bit in that case. This means that on
macOS, a client disconnect may take up to a second to be detected,
but that's better than not being detected at all.
Fixes#7584.
Adds a new boolean structured attribute
`outputChecks.<output>.unsafeDiscardReferences` which disables scanning
an output for runtime references.
__structuredAttrs = true;
outputChecks.out.unsafeDiscardReferences = true;
This is useful when creating filesystem images containing their own embedded Nix
store: they are self-contained blobs of data with no runtime dependencies.
Setting this attribute requires the experimental feature
`discard-references` to be enabled.
This makes the position object used in exceptions abstract, with a
method getSource() to get the source code of the file in which the
error originated. This is needed for lazy trees because source files
don't necessarily exist in the filesystem, and we don't want to make
libutil depend on the InputAccessor type in libfetcher.
When debugging nix expressions the outermost trace tends to be more useful
than the innermost. It is therefore printed last to save developers from
scrolling.
The new experimental feature 'cgroups' enables the use of cgroups for
all builds. This allows better containment and enables setting
resource limits and getting some build stats.
- call close explicitly in writeFile to prevent the close exception
from being ignored
- fsync after writing schema file to flush data to disk
- fsync schema file parent to flush metadata to disk
https://github.com/NixOS/nix/issues/7064
This was caused by -L calling setLogFormat() again, which caused the
creation of a new progress bar without destroying the old one. So we
had two progress bars clobbering each other.
We should change 'logger' to be a smart pointer, but I'll do that in a
future PR.
Fixes#6931.
Rather than directly copying the source to its dest, copy it first to a
temporary location, and eventually move that temporary.
That way, the move is at least atomic from the point-of-view of the destination
Jonas Chevalier
Yorick
Robert Hensing
Jörg Thalheim