Commit graph

1317 commits

Author SHA1 Message Date
Cole Helbling
e135d223f6 libutil: save fd to cwd instead of cwd itself 2022-04-04 08:32:45 -07:00
Cole Helbling
e5b70d47aa libutil: cleanup savedCwd logic
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
2022-04-04 08:20:11 -07:00
Cole Helbling
2a45cf54e4 libutil: Properly guard self-allocating getcwd on GNU
It's a GNU extension, as pointed out by pennae.
2022-04-01 12:20:34 -07:00
Cole Helbling
7f5caaa7c0 libutil: Don't use std::filesystem
Just in case making libutil depend on std::filesystem is unacceptable,
here is the non-filesystem approach.
2022-04-01 10:24:31 -07:00
aszlig
435848cef1 libutil: Fix restoring mount namespace
I regularly pass around simple scripts by using nix-shell as the script
interpreter, eg. like this:

    #!/usr/bin/env nix-shell
    #!nix-shell -p dd_rescue coreutils bash -i bash

While this works most of the time, I recently had one occasion where it
would not and the above would result in the following:

    $ sudo ./myscript.sh
    bash: ./myscript.sh: No such file or directory

Note the "sudo" here, because this error only occurs if we're root.

The reason for the latter is because running Nix as root means that we
can directly access the store, which makes sure we use a filesystem
namespace to make the store writable. XXX - REWORD!

So when stracing the process, I stumbled on the following sequence:

    openat(AT_FDCWD, "/proc/self/ns/mnt", O_RDONLY) = 3
    unshare(CLONE_NEWNS)                            = 0
    ... later ...
    getcwd("/the/real/cwd", 4096)                   = 14
    setns(3, CLONE_NEWNS)                           = 0
    getcwd("/", 4096)                               = 2

In the whole strace output there are no calls to chdir() whatsoever, so
I decided to look into the kernel source to see what else could change
directories and found this[1]:

    /* Update the pwd and root */
    set_fs_pwd(fs, &root);
    set_fs_root(fs, &root);

The set_fs_pwd() call is roughly equivalent to a chdir() syscall and
this is called when the setns() syscall is invoked[2].

[1]: b14ffae378/fs/namespace.c (L4659)
[2]: b14ffae378/kernel/nsproxy.c (L346)
2022-04-01 09:30:52 -07:00
Eelco Dolstra
c9a29d0d92
Merge pull request #6227 from NixOS/impure-derivations-ng
Impure derivations
2022-03-31 19:58:35 +02:00
Eelco Dolstra
5cd72598fe Add support for impure derivations
Impure derivations are derivations that can produce a different result
every time they're built. Example:

  stdenv.mkDerivation {
    name = "impure";
    __impure = true; # marks this derivation as impure
    outputHashAlgo = "sha256";
    outputHashMode = "recursive";
    buildCommand = "date > $out";
  };

Some important characteristics:

* This requires the 'impure-derivations' experimental feature.

* Impure derivations are not "cached". Thus, running "nix-build" on
  the example above multiple times will cause a rebuild every time.

* They are implemented similar to CA derivations, i.e. the output is
  moved to a content-addressed path in the store. The difference is
  that we don't register a realisation in the Nix database.

* Pure derivations are not allowed to depend on impure derivations. In
  the future fixed-output derivations will be allowed to depend on
  impure derivations, thus forming an "impurity barrier" in the
  dependency graph.

* When sandboxing is enabled, impure derivations can access the
  network in the same way as fixed-output derivations. In relaxed
  sandboxing mode, they can access the local filesystem.
2022-03-31 13:43:20 +02:00
Eelco Dolstra
0fe8849914
Merge pull request #6337 from danpls/fix-to-json-repl
libexpr: Throw the correct error in toJSON
2022-03-31 11:33:16 +02:00
Eelco Dolstra
28309352d9 replaceEnv(): Pass newEnv by reference 2022-03-31 10:39:53 +02:00
Daniel Pauls
629edd43ba libutil: Change return value of addTrace to void
The return value of BaseError::addTrace(...) is never used and
error-prone as subclasses calling it will return a BaseError instead of
the subclass.
This commit changes its return value to be void.
2022-03-30 18:37:32 +02:00
Maximilian Bosch
c85467a1b6
Revert "TarArchive: Small refactoring"
This reverts commit 50a35860ee.

With this change Nix fails to open bzip2 logfiles that were created from
builds with no stdout/stderr.
2022-03-24 22:30:46 +01:00
Eelco Dolstra
f902f3c2cb Add experimental feature 'fetch-closure' 2022-03-24 21:33:33 +01:00
Eelco Dolstra
a53c1dc96d
Merge pull request #6245 from trofi/fix-nix-store-gc-limit-auto-optimise-store
nix store gc: account for auto-optimised store
2022-03-16 09:19:57 +01:00
Maximilian Bosch
34e20c164c
libfetchers/path: set lastModified to path's mtime
When importing e.g. a local `nixpkgs` in a flake to test a change like

    {
      inputs.nixpkgs.url = path:/home/ma27/Projects/nixpkgs;
      outputs = /* ... */
    }

then the input is missing a `lastModified`-field that's e.g. used in
`nixpkgs.lib.nixosSystem`. Due to the missing `lastMoified`-field, the
mtime is set to 19700101:

    result -> /nix/store/b7dg1lmmsill2rsgyv2w7b6cnmixkvc1-nixos-system-nixos-22.05.19700101.dirty

With this change, the `path`-fetcher now sets a `lastModified` attribute
to the `mtime` just like it's the case in the `tarball`-fetcher already.
When building NixOS systems with `nixpkgs` being a `path`-input and this
patch, the output-path now looks like this:

    result -> /nix/store/ld2qf9c1s98dxmiwcaq5vn9k5ylzrm1s-nixos-system-nixos-22.05.20220217.dirty
2022-03-15 12:32:11 +01:00
Sergei Trofimovich
6b1872312f nix store gc: account for auto-optimised store
Before the change on a system with `auto-optimise-store = true`:

    $ nix store gc --verbose --max 1

deleted all the paths instead of one path (we requested 1 byte limit).

It happens because every file in `auto-optimise-store = true` has at
least 2 links: file itself and a link in /nix/store/.links/ directory.

The change conservatively assumes that any file that has one (as before)
or two links (assume auto-potimise mode) will free space.

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
2022-03-13 07:24:48 +00:00
Eelco Dolstra
31a392dfe2 Merge pull request #5865 from pennae/memory-friendliness
be more memory friendly
2022-03-11 11:52:39 +01:00
pennae
8e2eaaaf69 make Finally more local
no need for function<> with c++17 deduction. this saves allocations and virtual
calls, but has the same semantics otherwise. not going through function has the
side effect of giving compilers more insight into the cleanup code, so we need a
few local warning disables.
2022-03-09 00:16:50 +01:00
pennae
47baa9d43c make Pos smaller
reduces peak hep memory use on eval of our test system from 264.4MB to 242.3MB,
possibly also a slight performance boost.

theoretically memory use could be cut down by another eight bytes per Pos on
average by turning it into a tuple containing an index into a global base
position table with row and column offsets, but that doesn't seem worth the
effort at this point.
2022-03-08 23:30:18 +01:00
Eelco Dolstra
30ddd37873 Merge branch 'cli-suggestions' of https://github.com/thufschmitt/nix 2022-03-07 19:47:45 +01:00
regnat
dcf4f77fac Merge or-suggestions.hh into suggestions.hh
No real need for keeping a separate header for such a simple class.

This requires changing a bit `OrSuggestions<T>::operator*` to not throw
an `Error` to prevent a cyclic dependency. But since this error is only
thrown on programmer error, we can replace the whole method by a direct
call to `std::get` which will raise its own assertion if needs be.
2022-03-07 17:49:02 +01:00
regnat
313bbc07a8 Implement operator<< for Suggestions
That way there’s no need to explicitely convert it to a string when
printing it
2022-03-07 10:09:10 +01:00
regnat
fd45d85b41 Move OrSuggestions to its own header
Prevents a recursive inclusion
2022-03-07 10:09:10 +01:00
regnat
98e361ad4c Also display suggestions for the commands using the eval cache
Make `nix build .#nix-armv8l-linux` work for example
2022-03-07 10:09:10 +01:00
regnat
2405bbbb5e Add some tests for the suggestions 2022-03-07 10:09:10 +01:00
regnat
c0792b1546 Implement a suggestions mechanism
Each `Error` class now includes a set of suggestions, and these are printed by
the top-level handler.
2022-03-07 10:09:09 +01:00
Théophane Hufschmitt
a2ace54fe4
Merge pull request #6029 from Ma27/nix-log-ssh-ng
ssh-ng: also store build logs to make them accessible by `nix log`
2022-03-07 09:51:40 +01:00
John Ericson
6636202356 Factor out a GcStore interface
Starts progress on #5729.

The idea is that we should not have these default methods throwing
"unimplemented". This is a small step in that direction.

I kept `addTempRoot` because it is a no-op, rather than failure. Also,
as a practical matter, it is called all over the place, while doing
other tasks, so the downcasting would be annoying.

Maybe in the future I could move the "real" `addTempRoot` to `GcStore`,
and the existing usecases use a `tryAddTempRoot` wrapper to downcast or
do nothing, but I wasn't sure whether that was a good idea so with a
bias to less churn I didn't do it yet.
2022-03-03 19:01:25 +00:00
Eelco Dolstra
6097790863 Fix segfault in headerCallback()
https://hydra.nixos.org/build/168594664
2022-03-03 11:11:16 +01:00
Anders Kaseorg
b5cd3e2d5c filterANSIEscapes: Ignore BEL character
GCC is not as good at music as it seems to think it is.  Fixes #4546.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
2022-03-01 15:35:42 -08:00
Maximilian Bosch
6a8f1b548f
logging.hh: json.hpp -> json_fwd.hpp 2022-02-28 17:27:52 +01:00
Maximilian Bosch
cd92ea5885
libstore/derivation-goal: avoid double-parsing of JSON messages
To avoid that JSON messages are parsed twice in case of
remote builds with `ssh-ng://`, I split up the original
`handleJSONLogMessage` into three parts:

* `parseJSONMessage(const std::string&)` checks if it's a message in the
  form of `@nix {...}` and tries to parse it (and prints an error if the
  parsing fails).
* `handleJSONLogMessage(nlohmann::json&, ...)` reads the fields from the
  message and passes them to the logger.
* `handleJSONLogMessage(const std::string&, ...)` behaves as before, but
  uses the two functions mentioned above as implementation.

In case of `ssh-ng://`-logs the first two methods are invoked manually.
2022-02-28 17:27:52 +01:00
Eelco Dolstra
df552ff53e Remove std::string alias (for real this time)
Also use std::string_view in a few more places.
2022-02-25 16:13:02 +01:00
Eelco Dolstra
14b38d0887 xml-writer: Remove std aliases 2022-02-25 16:13:02 +01:00
Eelco Dolstra
36c7b12f33 Remove std::string alias 2022-02-21 16:37:25 +01:00
Eelco Dolstra
1ac2664472 Remove std::vector alias 2022-02-21 16:32:34 +01:00
Eelco Dolstra
fe9afb65bb Remove std::set alias 2022-02-21 16:28:23 +01:00
Eelco Dolstra
afcdc7606c Remove std::list alias 2022-02-21 16:25:12 +01:00
Eelco Dolstra
e2422c4582
Merge pull request #6052 from hercules-ci/issue-3294-fix-interruptCallback-deadlock
Fix deadlocked nix-daemon zombies on darwin #3294
2022-02-21 16:21:45 +01:00
Robert Hensing
ddb6740e7d triggerInterrupt: Refactor to use break 2022-02-21 15:43:43 +01:00
Sergei Trofimovich
3ec02deb20 Make sure no exceptions leave ignoreException()
I noticed that occasional Ctrl-C leaves *.lock files around.
`nix-daemon`'s journal logs contained crashes like:

    nix-daemon[30416]: terminate called after throwing an instance of 'nix::SysError'
    nix-daemon[30416]:   what():  error: writing to file: Broken pipe

And core dump backtraces pointed at `teriminate()` call from
destructors:

    ...
    _Unwind_Resume ()
    nix::ignoreException() ()
    nix::LocalDerivationGoal::~LocalDerivationGoal()
    ...

    void ignoreException()
    {
        try {
            throw;
        } catch (std::exception & e) {
            printError("error (ignored): %1%", e.what());
        }
    }

The crashes happen when client side closes early and printError() throws
an IO error.

The change wraps `ignoreException()` into blanket `try { ... } catch (...) {}`.

Closes: https://github.com/NixOS/nix/issues/6046
2022-02-07 16:20:56 +00:00
Robert Hensing
c3b942e0fc Don't hold interruptCallbacks lock during interrupt handling
This changes the representation of the interrupt callback list to
be safe to use during interrupt handling.

Holding a lock while executing arbitrary functions is something to
avoid in general, because of the risk of deadlock.

Such a deadlock occurs in https://github.com/NixOS/nix/issues/3294
where ~CurlDownloader tries to deregister its interrupt callback.

This happens during what seems to be a triggerInterrupt() by the
daemon connection's MonitorFdHup thread. This bit I can not confirm
based on the stack trace though; it's based on reading the code,
so no absolute certainty, but a smoking gun nonetheless.
2022-02-06 13:53:28 +01:00
Eelco Dolstra
cd35bbbeef Merge branch 'more-stringviews' of https://github.com/pennae/nix 2022-02-02 12:38:37 +01:00
Will Dietz
a0357abda7 canonPath: fix missing slash when resolving links
Fixes #6017
2022-01-29 16:32:27 -06:00
pennae
d439dceb3b optionally return string_view from coerceToString
we'll retain the old coerceToString interface that returns a string, but callers
that don't need the returned value to outlive the Value it came from can save
copies by using the new interface instead. for values that weren't stringy we'll
pass a new buffer argument that'll be used for storage and shouldn't be
inspected.
2022-01-27 22:15:30 +01:00
pennae
41d70a2fc8 return string_views from forceString*
once a string has been forced we already have dynamic storage allocated for it,
so we can easily reuse that storage instead of copying.
2022-01-27 17:15:43 +01:00
pennae
0d7fae6a57 convert a for more utilities to string_view 2022-01-27 17:15:43 +01:00
Eelco Dolstra
fcf3528ad1 Remove unused Rust stuff
In particular we were still compiling rust-ffi.cc even though we're
not using it.
2022-01-25 11:58:00 +01:00
Eelco Dolstra
7afbdf2545 hiliteMatches(): Style fixes, pass more stuff by reference 2022-01-24 14:47:34 +01:00
regnat
ffb28eaa1e Add a small documentation for hiliteMatches 2022-01-24 10:07:02 +01:00
Fishhh
f82a426502
Add some tests for hiliteMatches in libutil 2022-01-21 20:10:54 +01:00