It is good to propagate the underlying error so whether or not we use a
process to deal with path length issues is not observable.
Also, as these wrapper functions got more and more complex, the code
duplication got worse and worse. The new `bindConnectProcHelper`
function deduplicates them.
Most of this is a `catch SysError` -> `catch SystemError` sed. This
is a rather pure-churn change I would like to get out of the way. **The
intersting part is `src/libutil/error.hh`.**
On Unix, we will only throw the `SysError` concrete class, which has
the same constructors that `SystemError` used to have.
On Windows, we will throw `WinError` *and* `SysError`. `WinError`
(which will be created in a later PR), will use a `DWORD` instead of
`int` error value, and `GetLastError()`, which is the Windows equivalent
of the `errno` machinery. Windows will *also* use `SysError` because
Window's "libc" (MSVCRT) implements the POSIX interface, and we use it
too.
As the docs describe, while we *throw* one of the 3 choices above (2
concrete classes or the alias), we should always *catch* `SystemError`.
This ensures no matter how the implementation changes for Windows (e.g.
between `SysError` and `WinError`) the catching logic stays the same
and stays correct.
Co-Authored-By volth <volth@volth.com>
Co-Authored-By Eugene Butler <eugene@eugene4.com>
Previously, there were two mostly-identical value printers -- one in
`libexpr/eval.cc` (which didn't force values) and one in
`libcmd/repl.cc` (which did force values and also printed ANSI color
codes).
This PR unifies both of these printers into `print.cc` and provides a
`PrintOptions` struct for controlling the output, which allows for
toggling whether values are forced, whether repeated values are tracked,
and whether ANSI color codes are displayed.
Additionally, `PrintOptions` allows tuning the maximum number of
attributes, list items, and bytes in a string that will be displayed;
this makes it ideal for contexts where printing too much output (e.g.
all of Nixpkgs) is distracting. (As requested by @roberth in
https://github.com/NixOS/nix/pull/9554#issuecomment-1845095735)
Please read the tests for example output.
Future work:
- It would be nice to provide this function as a builtin, perhaps
`builtins.toStringDebug` -- a printing function that never fails would
be useful when debugging Nix code.
- It would be nice to support customizing `PrintOptions` members on the
command line, e.g. `--option to-string-max-attrs 1000`.
Also move `SourcePath` into `libutil`.
These changes allow `error.hh` and `error.cc` to access source path and
position information, which we can use to produce better error messages
(for example, we could consider omitting filenames when two or more
consecutive stack frames originate from the same file).
This sets up infrastructure in libutil to allow for signing other than
by a secret key in memory. #9076 uses this to implement remote signing.
(Split from that PR to allow reviewing in smaller chunks.)
Co-Authored-By: Raito Bezarius <masterancpp@gmail.com>
This fixes a segfault on infinite function call recursion (rather than
infinite thunk recursion) by tracking the function call depth in
`EvalState`.
Additionally, to avoid printing extremely long stack traces, stack
frames are now deduplicated, with a `(19997 duplicate traces omitted)`
message. This should only really be triggered in infinite recursion
scenarios.
Before:
$ nix-instantiate --eval --expr '(x: x x) (x: x x)'
Segmentation fault: 11
After:
$ nix-instantiate --eval --expr '(x: x x) (x: x x)'
error: stack overflow
at «string»:1:14:
1| (x: x x) (x: x x)
| ^
$ nix-instantiate --eval --expr '(x: x x) (x: x x)' --show-trace
error:
… from call site
at «string»:1:1:
1| (x: x x) (x: x x)
| ^
… while calling anonymous lambda
at «string»:1:2:
1| (x: x x) (x: x x)
| ^
… from call site
at «string»:1:5:
1| (x: x x) (x: x x)
| ^
… while calling anonymous lambda
at «string»:1:11:
1| (x: x x) (x: x x)
| ^
… from call site
at «string»:1:14:
1| (x: x x) (x: x x)
| ^
(19997 duplicate traces omitted)
error: stack overflow
at «string»:1:14:
1| (x: x x) (x: x x)
| ^
more buffers that can be uninitialized and on the stack. small
difference, but still worth doing.
before:
Benchmark 1: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
Time (mean ± σ): 6.963 s ± 0.011 s [User: 5.330 s, System: 1.421 s]
Range (min … max): 6.943 s … 6.974 s 10 runs
after:
Benchmark 1: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
Time (mean ± σ): 6.952 s ± 0.015 s [User: 5.294 s, System: 1.452 s]
Range (min … max): 6.926 s … 6.974 s 10 runs
as written the comparisons generate copies, even though it looks as
though they shouldn't.
before:
Time (mean ± σ): 4.396 s ± 0.002 s [User: 3.894 s, System: 0.501 s]
Range (min … max): 4.393 s … 4.399 s 10 runs
after:
Time (mean ± σ): 4.260 s ± 0.003 s [User: 3.754 s, System: 0.505 s]
Range (min … max): 4.257 s … 4.266 s 10 runs
This keeps hint messages, source location information, and source code
snippets grouped together, while making stack traces shorter (so that
more stack frames can be viewed on the same terminal).
Before:
error:
… while evaluating the attribute 'body'
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:4:3:
3|
4| body = x "x";
| ^
5| }
… from call site
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:4:10:
3|
4| body = x "x";
| ^
5| }
… while calling 'x'
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:2:7:
1| let {
2| x = arg: assert arg == "y"; 123;
| ^
3|
error: assertion '(arg == "y")' failed
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:2:12:
1| let {
2| x = arg: assert arg == "y"; 123;
| ^
3|
After:
error:
… while evaluating the attribute 'body'
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:4:3:
3|
4| body = x "x";
| ^
5| }
… from call site
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:4:10:
3|
4| body = x "x";
| ^
5| }
… while calling 'x'
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:2:7:
1| let {
2| x = arg: assert arg == "y"; 123;
| ^
3|
error: assertion '(arg == "y")' failed
at /Users/wiggles/nix/tests/functional/lang/eval-fail-assert.nix:2:12:
1| let {
2| x = arg: assert arg == "y"; 123;
| ^
3|
The code has already been fixed (yay!) so what is left of this commit is
just updating the API docs.
Co-authored-by: Cole Helbling <cole.e.helbling@outlook.com>
AppleDouble files were extracted differently on macOS machines than on other
UNIX's.
Setting `archive_read_set_format_option(this->archive, NULL ,"mac-ext",NULL)`
fixes this problem, since it just ignores the AppleDouble file and treats it as
a normal one.
This was a problem since it caused source archives to be different between macOS
and Linux.
Ref: nixos/nix#9290
* Factor out the default `MultiCommand` behavior
All the `MultiCommand`s had (nearly) the same behavior when called
without a subcommand.
Factor out this behavior into the `NixMultiCommand` class.
* Display the list of available subcommands when none is specified
Whenever a user runs a command that excepts a subcommand, add the list
of available subcommands to the error message.
* Print the multi-command lists as Markdown lists
This takes more screen real estate, but is also much more readable than
a comma-separated list
without knowing a lot of context, it's not clear who "we" are in that
text. I'm also strongly opposed to adding procedural notes into
a reference manual; it just won't age well.
this change leaves a factual description of the experimental feature and
its purpose.
Today, with the tests inside a `tests` intermingled with the
corresponding library's source code, we have a few problems:
- We have to be careful that wildcards don't end up with tests being
built as part of Nix proper, or test headers being installed as part
of Nix proper.
- Tests in libraries but not executables is not right:
- It means each executable runs the previous unit tests again, because
it needs the libraries.
- It doesn't work right on Windows, which doesn't want you to load a
DLL just for the side global variable . It could be made to work
with the dlopen equivalent, but that's gross!
This reorg solves these problems.
There is a remaining problem which is that sibbling headers (like
`hash.hh` the test header vs `hash.hh` the main `libnixutil` header) end
up shadowing each other. This PR doesn't solve that. That is left as
future work for a future PR.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This makes for more useful manual table of contents, that displays the
information at a glance.
The `nix help-stores` command is kept as-is, even though it will show up
in the manual with the same information as these pages due to the way it
is written as a "`--help`-style" command. Deciding what to do with that
command is left for a later PR.
This change also lists all store types at the top of the respective overview page.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems
This allows templates such as `NLOHMANN_DEFINE_TYPE_*` templates and other generators with things like `std::vector<std::optional<T>>`.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
Fixes:
warning: destructor called on non-final 'nix::ParseUnquoted' that has virtual functions but non-virtual destructor [-Wdelete-non-abstract-non-virtual-dtor]
Closes#9343
See that issue for motivation.
Installing these is disabled by default, but we enable it (and the
additional output we want isntall these too so as not to clutter the
existing ones) to use in cross builds and dev shells.
This is the core functionality but just unit-tested and not yet made
part of the store layer. This is because there is some tech debt around
(a) repeated boilerplate hashing objects (b) better integration of the
new `SourceAccessor` type that needs to be cleaned up first.
Part of RFC 133
Co-Authored-By: Matthew Bauer <mjbauer95@gmail.com>
Co-Authored-By: Carlo Nucera <carlo.nucera@protonmail.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Florian Klink <flokli@flokli.de>
As discussed in our last meeting, we need a bit more time, but we are
"time boxing" the work left to do to ensure there is not unbounded
delay.
Rather than putting it back underneath `flakes`, though, put it
underneath its own `fetch-tree` experimental feature (which `flakes`
includes/implies). This signals our commitment to the plan to stabilize
it first without waiting to go through the rest of Flakes, and also will
give users a "release candidate" when we get closer to stabilization.
This reverts commit 4112dd1fc9.
Enables shebang usage of nix shell. All arguments with `#! nix` get
added to the nix invocation. This implementation does NOT set any
additional arguments other than placing the script path itself as the
first argument such that the interpreter can utilize it.
Example below:
```
#!/usr/bin/env nix
#! nix shell --quiet
#! nix nixpkgs#bash
#! nix nixpkgs#shellcheck
#! nix nixpkgs#hello
#! nix --ignore-environment --command bash
# shellcheck shell=bash
set -eu
shellcheck "$0" || exit 1
function main {
hello
echo 0:"$0" 1:"$1" 2:"$2"
}
"$@"
```
fix: include programName usage
EDIT: For posterity I've changed shellwords to shellwords2 in order
not to interfere with other changes during a rebase.
shellwords2 is removed in a later commit. -- roberth
Users may select specific outputs using the ^output syntax or selecting
any output using ^*.
URL parsing currently doesn't support these kinds of output references:
parsing will fail.
Currently `queryRegex` was reused for URL fragments, which didn't
include support for ^. Now queryRegex has been split from fragmentRegex,
where only the fragmentRegex supports ^.
`Store::pathInfoToJSON` was a rather baroque functions, being full of
parameters to support both parsed derivations and `nix path-info`. The
common core of each, a simple `dValidPathInfo::toJSON` function, is
factored out, but the rest of the logic is just duplicated and then
specialized to its use-case (at which point it is no longer that
duplicated).
This keeps the human oriented CLI logic (which is currently unstable)
and the core domain logic (export reference graphs with structured
attrs, which is stable), separate, which I think is better.
All OS and IO operations should be moved out, leaving only some misc
portable pure functions.
This is useful to avoid copious CPP when doing things like Windows and
Emscripten ports.
Newly exposed functions to break cycles:
- `restoreSignals`
- `updateWindowSize`
