Code review comment for lp:~smoser/curtin/trunk.no-translations

> wrt faster for the sed. possibly, although it would incur overhead of 'sed'
> fork.
> the bigger issue is it is lossy. a sources.list file might have some 'deb-src'
> lines commented out and others not (in fact base cloud image does have that).
> so my saving of a copy is safer in that regard.

This a moot point now, but sed -i<suffix> would retain the original, so we wouldn't be lossy; just messy with additional files and IO.