Some nspawn subshells ignore errors

[kpcyrd]

I noticed this error:

(13/21) Warn about old perl modules
(14/21) Updating fontconfig cache...
(15/21) Probing GDK-Pixbuf loader modules...
(16/21) Updating GIO module cache...
(17/21) Compiling GSettings XML schema files...
(18/21) Probing GTK3 input method modules...
(19/21) Updating icon theme caches...
(20/21) Updating the info directory file...
(21/21) Updating the desktop file MIME type cache...
Installing devtools from https://archive.archlinux.org/packages/d/devtools-20220207-2-any.pkg.tar.zst
:: Retrieving packages...
 devtools-20220207-2-any.pkg.tar.zst failed to download
error: failed retrieving file 'devtools-20220207-2-any.pkg.tar.zst' from archive.archlinux.org : Connection timeout after 10000 ms
warning: failed to retrieve some files
cp: cannot stat '/usr/share/devtools/makepkg-x86_64.conf': No such file or directory
%

The rebuild failing due to the connection timeout is expected, but it seems the error was ignored and the script continued running (attempting to copy a file).

This is because the code is running in a nspawn subshell that doesn't use -x: https://github.com/archlinux/archlinux-repro/blob/7768f33f1e9ab8501eda68ed885974cb33bbb0e8/repro.in#L481-L502