libfetchers uses `git_mempack_write_thin_pack` which was introduced in libgit2-1.9.0
This avoids error like:
../src/libfetchers/git-utils.cc: In member function ‘virtual void nix::GitRepoImpl::flush()’:
../src/libfetchers/git-utils.cc:270:13: error: ‘git_mempack_write_thin_pack’ was not declared in this scope
270 | git_mempack_write_thin_pack(mempack_backend, packBuilder.get())
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
on older libgit2 (like 1.7.2 in Centos Stream 10)
This is a follow-up to 6ec50ba736, which
also almost halves the compile times on clang for subprojects that use PCH.
`-fpch-instantiate-templates` is a clang-only option to force the instantiation
of templates once in the PCH itself, not all of the translation units that
it gets included to. This really cuts down on the overhead from nlohmann::json
and std::format code:
48244 ms: nlohmann::basic_json<>::parse<const char *> (76 times, avg 634 ms)
36193 ms: nlohmann::basic_json<>::basic_json (310 times, avg 116 ms)
28307 ms: nlohmann::detail::parser<nlohmann::basic_json<>, nlohmann::detail::i... (76 times, avg 372 ms)
20334 ms: nlohmann::detail::parser<nlohmann::basic_json<>, nlohmann::detail::i... (76 times, avg 267 ms)
17387 ms: nlohmann::basic_json<>::json_value::json_value (389 times, avg 44 ms)
16822 ms: std::vformat_to<std::__format::_Sink_iter<char>> (76 times, avg 221 ms)
16771 ms: std::__format::__do_vformat_to<std::__format::_Sink_iter<char>, char... (76 times, avg 220 ms)
12160 ms: std::vformat_to<std::__format::_Sink_iter<wchar_t>> (76 times, avg 160 ms)
12127 ms: std::__format::__do_vformat_to<std::__format::_Sink_iter<wchar_t>, w... (76 times, avg 159 ms)
10397 ms: nlohmann::detail::json_sax_dom_callback_parser<nlohmann::basic_json<... (76 times, avg 136 ms)
9118 ms: nlohmann::basic_json<>::data::data (76 times, avg 119 ms)
Initially done by Jade Lovelace <lix@jade.fyi> in https://gerrit.lix.systems/c/lix/+/1842.
We are doing basically the same, but unconditionally. It would be
a huge pain to add a pch option for all subprojects to just support the
usecase of using clangd in a gcc devshell.
In total, this basically halves the frontend times for nix-util and nix-store
to the point that the most expensive part of the build is linking.
(nix-store before):
```
**** Time summary:
Compilation (77 times):
Parsing (frontend): 243.4 s
Codegen & opts (backend): 140.3 s
```
(nix-store after):
```
**** Time summary:
Compilation (77 times):
Parsing (frontend): 120.2 s
Codegen & opts (backend): 141.2 s
```
This adds a GHA jobs to help analyze build times
and its regressions. It is based on `clangStdenv` with `-ftime-trace`
together with `ClangBuildAnalyzer` to prepare markdown summary for
individual components.
This also has the minor benefit of dogfooding CA and impure derivations.
Users can access these through the `lib.makeComponents` return value,
so it's helpful to briefly explain some of them.
This doesn't replace `meta.description`, but supplements it.
(TODO: improve `meta.description`)
This was carefully refactored by inlining some Nixpkgs definitions
like `generateSplicesForMkScope`, so the memoization properties
should remain the same.
* It is tough to contribute to a project that doesn't use a formatter,
* It is extra hard to contribute to a project which has configured the formatter, but ignores it for some files
* Code formatting makes it harder to hide obscure / weird bugs by accident or on purpose,
Let's rip the bandaid off?
Note that PRs currently in flight should be able to be merged relatively easily by applying `clang-format` to their tip prior to merge.
Previously, `nix help shell` failed with "Nix has no subcommand 'shell'" despite `nix shell --help`
working correctly. This happened because the `shell` command is actually an alias for `env shell`,
and the help system wasn't resolving aliases when looking up documentation.
This patch modifies the `showHelp` function to check for and resolve aliases before generating the
manpage name, ensuring that shorthand commands like `shell` get proper help documentation.
Closes: #13431
Move init() call from constructor to openStore() method to avoid calling
virtual methods during object construction. This prevents undefined
behavior when virtual methods are called before the object is fully
constructed.
Move init() call from constructor to openStore() method to avoid calling
virtual methods during object construction. This prevents undefined
behavior when virtual methods are called before the object is fully
constructed.
When `file://` is used accidentally in a flake as the source it is
expected to be a tarball by default.
Add some friendlier error messages to either inform the user this is not
in fact a tarball or if it's a git directory, let them know they can use
`git+file`.
fixes#12935
Users have complained that fetchGit is flaky however the culprit is
likely that `git fetch` was unable itself to download the repository for
whatever reason (i.e. poor network etc..)
Nothing was checking the status of `git fetch` and the error message
that would eventually surface to the users were that the commit was not
found.
Add explicit error checking for status code from `git fetch` and return
a message earlier on to indicate that the failure was from that point.
fixes#10431
