As it turns out the orignal implementation of symlink_exists cannot be
used in Nix because it did now std::filesystem::filesystem_error.
The new implementation fixes that but is now actually the same as
pathExists except for the path type.
For example, instead of doing
#include "nix/store-config.hh"
#include "nix/derived-path.hh"
Now do
#include "nix/store/config.hh"
#include "nix/store/derived-path.hh"
This was originally planned in the issue, and also recent requested by
Eelco.
Most of the change is purely mechanical. There is just one small
additional issue. See how, in the example above, we took this
opportunity to also turn `<comp>-config.hh` into `<comp>/config.hh`.
Well, there was already a `nix/util/config.{cc,hh}`. Even though there
is not a public configuration header for libutil (which also would be
called `nix/util/config.{cc,hh}`) that's still confusing, To avoid any
such confusion, we renamed that to `nix/util/configuration.{cc,hh}`.
Finally, note that the libflake headers already did this, so we didn't
need to do anything to them. We wouldn't want to mistakenly get
`nix/flake/flake/flake.hh`!
Progress on #7876
The short answer for why we need to do this is so we can consistently do
`#include "nix/..."`. Without this change, there are ways to still make
that work, but they are hacky, and they have downsides such as making it
harder to make sure headers from the wrong Nix library (e..g.
`libnixexpr` headers in `libnixutil`) aren't being used.
The C API alraedy used `nix_api_*`, so its headers are *not* put in
subdirectories accordingly.
Progress on #7876
We resisted doing this for a while because it would be annoying to not
have the header source file pairs close by / easy to change file
path/name from one to the other. But I am ameliorating that with
symlinks in the next commit.
If we previously fetched by revision, the output of "git ls-remote"
won't start with the expected line like
ref: refs/heads/master HEAD
but will be something like
5c4410e3b9891c05ab40d723de78c6f0be45ad30 refs/heads/5c4410e3b9891c05ab40d723de78c6f0be45ad30
This then causes Nix to treat that revision as a refname, which then
leads to warnings like
warning: could not update cached head '5c4410e3b9891c05ab40d723de78c6f0be45ad30' for 'file:///tmp/repo'
This causes Git to create a local ref named refs/head/<rev>, e.g.
$ git -C ~/.cache/nix/gitv3/11irpim06vj4h6c0w8yls6kx4hvl0qd0gr1fvk47n76g6wf1s1vk ls-remote --symref .
5c4410e3b9891c05ab40d723de78c6f0be45ad30 refs/heads/5c4410e3b9891c05ab40d723de78c6f0be45ad30
7f6bde8a20de4cccc2256f088bc5af9dbe38881d refs/heads/7f6bde8a20de4cccc2256f088bc5af9dbe38881d
which confuses readHead(), leading to errors like
fatal: Refusing to point HEAD outside of refs/
warning: could not update cached head 'd275d93aa0bb8a004939b2f1e87f559f989453be' for 'file:///tmp/repo'
Git interprets them as part of the file name, so passing parameters
like 'rev' breaks. Only relevant for testing (when _NIX_FORCE_HTTP is
set) and local bare repos.
Fixes messages like 'copying /tmp/repo/tmp/repo to the store'. The
PosixSourceAccessor already sets the prefix. Setting the prefix twice
shouldn't be a problem, but GitRepoImpl::getAccessor() returns a
wrapped accessor so it's not actually idempotent.
Looks like some cruft has been left over from previous refactorings.
This removes dead variables, which should not have side effects in their
constructors. In cases where the variable initialization has a purpose
[[maybe_unused]] is inserted to silence compiler warnings.
This caused nlohmann/json.hpp to leak into a lot of compilation units,
which is slow (when not using precompiled headers).
Cuts build time from 46m24s to 42m5s (real time with -j24: 2m42s to
2m24s).
