See https://github.com/NixOS/nixpkgs/issues/15747. Previously this module was called `<unknown-file>`
in error messages, now it is called a bit more close to real:
```
module at /home/danbst/dev/nixpkgs/nixos/modules/virtualisation/containers.nix:470
```
The error can be reproduced like:
```
$ nix-instantiate ./nixos -A system --arg configuration '
{ fileSystems."/".device = "nodev";
boot.loader.grub.devices = [ "nodev" ];
containers.t.config.imports = [ <nixpkgs/nixos/modules/virtualisation/amazon-image.nix> ];
}'
```
Previously error was:
```
error: The unique option `containers.t.networking.hostName' is defined multiple times, in `/nix/var/nix/profiles/per-user/root/channels/nixpkgs/nixos/modules/virtualisation/amazon-image.nix' and `module at /home/danbst/dev/nixpkgs/nixos/modules/virtualisation/containers.nix:470'.
(use '--show-trace' to show detailed location information)
```
Now it is:
```
error: The unique option `containers.t.networking.hostName' is defined multiple times, in:
- /nix/var/nix/profiles/per-user/root/channels/nixpkgs/nixos/modules/virtualisation/amazon-image.nix
- module at /home/danbst/dev/nixpkgs/nixos/modules/virtualisation/containers.nix:470.
(use '--show-trace' to show detailed location information)
```
Related: https://github.com/NixOS/nixpkgs/issues/15747
The most immediate motivation for the source/patch reworking is to
upgrade the tree without needing to provide an updated version
with the fix and the upgrade as well.
Naturally the patch won't necessarily apply to all future versions,
but that's easy enough to check and happily appears to have no trouble
with this upgrade.
GCC 8.x is required to avoid the following error:
cc1plus: error: -Werror=class-memaccess: no option -Wclass-memaccess
If we build without "-Wno-error=class-memaccess" the build should fail
and the upstream requirements were raised from GCC 7 to GCC 8 anyway:
https://github.com/telegramdesktop/tdesktop/commit/b2f821d3deb65ade7416d28a18148176f6c40b34
The two additional patches are required to avoid build errors like this:
/build/source/Telegram/ThirdParty/qtlottie/src/bodymovin/bmbase.cpp:123:12:
error: invalid use of incomplete type 'class QDebug'
qWarning()
^
In file included from
/nix/store/1qk60bhxcf95iicms7mkyjq3h7lz136p-qtbase-5.12.0-dev/include/QtCore/qglobal.h:1200,
from
/nix/store/1qk60bhxcf95iicms7mkyjq3h7lz136p-qtbase-5.12.0-dev/include/QtCore/qalgorithms.h:43,
from
/nix/store/1qk60bhxcf95iicms7mkyjq3h7lz136p-qtbase-5.12.0-dev/include/QtCore/qlist.h:43,
from
/nix/store/1qk60bhxcf95iicms7mkyjq3h7lz136p-qtbase-5.12.0-dev/include/QtCore/QList:1,
from
/build/source/Telegram/ThirdParty/qtlottie/src/bodymovin/bmbase.h:31,
from
/build/source/Telegram/ThirdParty/qtlottie/src/bodymovin/bmbase.cpp:29:
/nix/store/1qk60bhxcf95iicms7mkyjq3h7lz136p-qtbase-5.12.0-dev/include/QtCore/qlogging.h:57:7:
note: forward declaration of 'class QDebug'
class QDebug;
^~~~~~