* fetchurl: fix and add extra KDE mirrors (#51480)
- The gwdg.de mirror has moved the relative path of its KDE tarballs
- Add new mirrors from Berkeley and MIT, which are on the list of officially supported mirrors
https://download.kde.org/extra/download-mirrors.html
* More KDE mirror touchups
- The official one is a redirect to HTTPS anyways, so go directly to HTTPS
- Add China USTC for Asian users
- Swap Finland university from FTP to HTTP
* fetchurl: keep one ftp KDE mirror
Docker images used to be, essentially, a linked list of layers. Each
layer would have a tarball and a json document pointing to its parent,
and the image pointed to the top layer:
imageA ----> layerA
|
v
layerB
|
v
layerC
The current image spec changed this format to where the Image defined
the order and set of layers:
imageA ---> layerA
|--> layerB
`--> layerC
For backwards compatibility, docker produces images which follow both
specs: layers point to parents, and images also point to the entire
list:
imageA ---> layerA
| |
| v
|--> layerB
| |
| v
`--> layerC
This is nice for tooling which supported the older version and never
updated to support the newer format.
Our `buildImage` code only supported the old version, so in order for
`buildImage` to properly generate an image based on another image
with `fromImage`, the parent image's layers must fully support the old
mechanism.
This is not a problem in general, but is a problem with
`buildLayeredImage`.
`buildLayeredImage` creates images with newer image spec, because
individual store paths don't have a guaranteed parent layer. Including
a specific parent ID in the layer's json makes the output less likely
to cache hit when published or pulled.
This means until now, `buildLayeredImage` could not be the input to
`buildImage`.
The changes in this PR change `buildImage` to only use the layer's
manifest when locating parent IDs. This does break buildImage on
extremely old Docker images, though I do wonder how many of these
exist.
This work has been sponsored by Target.
This ensures that RPATH entries like "/foo/build/bar" doesn't trigger a
match when TMPDIR is "/build/bar". (I've had this problem with a
prebuilt package.)
If there was no older file than $NIX_BUILD_TOP this would result in a
warning, e.g. with nix-info.
```
/nix/store/15kgcm8hnd99p7plqzx7p4lcr2jni4df-set-source-date-epoch-to-latest.sh: line 13: [: : integer expression expected
```
