We want the $doc, $man outputs to be symlinks pointing to nix-manual and
nix-manual.man. Creating the directories first makes the `ln` command
produce symlink $doc/${nix-manual} instead.
```
$file /nix/store/q4dwlnd36gpfajgfcp6hca2xwy068wjq-nix-2.27.1-man/rwh8ky3k040wyrywl8k2v5b3csdfbdg7-nix-manual-2.27.1-man
/nix/store/q4dwlnd36gpfajgfcp6hca2xwy068wjq-nix-2.27.1-man/rwh8ky3k040wyrywl8k2v5b3csdfbdg7-nix-manual-2.27.1-man:
symbolic link to /nix/store/rwh8ky3k040wyrywl8k2v5b3csdfbdg7-nix-manual-2.27.1-man
```
This is the reason `nix-env --help` is once again broken on 2.26/2.27/master
after 4108529.
This should fix a few packaging regressions.
`dev` also includes a merged `includes/`, which may be helpful until
inter-component includes are fixed properly.
This makes `nix.version` quicker to evaluate, which should speed up
package listing operations.
If you want an accurate count, use `lib.optionals` in your override
instead of `null` values.
1. Fix this eval error:
https://hydra.nixos.org/jobset/nix/master#tabs-errors
The dev package output (actually a separate derivation) needs to skip
this for cross just as the main package output does.
2. Deduplicate libs attrset and list.
3. Move `nix-functional-tests` to `checkInputs`.
With the Meson build system, we no longer need a `check` vs
`install-check` distinction, so it is simpler to just keeep
everything in one place.
- Multiple choices of stdenv are handled more consistently, especially for the dev
shells which were previously not done correctly.
- Some stray nix code was moving into the `packaging` directory
Just now there is a dependency on cachix, which means we cannot test
the installer in CI if forks do not have the necessary secrets set up.
We replace this with a simple http server that serves the installer and
can be both used in CI and locally.
We're not testing against these versions anymore.
If we bring that back (I would support that), we could do so in a clean
way, by making sure that the packaging we test against has a proper version
attribute.
I think I have failed to read the very long version-garbage-like
string for the second time now, leaving me oblivious to the crucial
info that a test failure happens in the context of an older daemon.
The new package output attributes are somewhat experimental, and
provided for compatibility most of all.
We'll see how well this goes before the changes proposed in
https://github.com/NixOS/nix/issues/6507
