Setting the image creation timestamp in the image metadata to a
constant date can cause problems with self-hosted container
registries, that need to e.g. prune old images. This timestamp is
also useful for debugging.
However, it is almost never useful to set the filesystem timestamp to
a constant value. Doing so not only causes the image to possibly no
longer be reproducible, but also removes any possibility of
deduplicating layers with other images, causing unnecessary storage
space usage.
Therefore, this commit introduces "mtime", a new parameter to
streamLayeredImage, which allows specifying the filesystem timestamps
separately from "created". For backwards compatibility, "mtime"
defaults to the value of "created".
This patch fixes occurances of writeTextFile invokations with
a destination set but without a leading slash. This would cause
an opaque build time error.
This documents:
* The existence of the `lhapdf` package (not particularly important)
* The existence of the `lhapdf.pdf_sets` attrset (important)
* The setup hook used in all of the entries in `lhapdf.pdf_sets`
(slightly important)
Part of #341479.
This documents:
* The `geant4.data` attrset introduced in #39514
* The setup hook for geant4
* The setup hook for the geant4.data packages
I also added a brief description of what Geant4 is.
Part of #341479
The darwin sandbox prevents this nix call from accessing `/nix/
store/.links` resulting in a build failure:
```
> error: getting status of '/nix/store/.links': Operation not permitted
```
Thanks to @emilazy for the workaround!
Fixes https://github.com/NixOS/nixpkgs/issues/339808
Found using https://github.com/serokell/xrefcheck, which unfortunately
can't trivially be enforced in CI because we also have the manual markdown
files that need post-processing to be valid
