- Document netinstall.conf a little,
- Add setting *required* which influences whether next is enabled or not
in case of missing or corrupt data,
- Enable *next* button only once some (any!) data is received.
This can be used to disallow stepping past the netinstall step when
there is no data (e.g. internet has failed between the welcome page
and the netinstall page).
When NetInstall receives YAML data, handle parser errors more gracefully:
show line and column, but because it's network data (not in a local file),
do some work to print out the actual data received.
FIXES#786
Package groups are divided into critical and non-critical
depending on whether we want all Calamares to fail if installing
a package in the group fails, or we are okay with just logging a
warning.
The distinction is configured in the YAML file listing the package
groups. By default, all groups are critical, to keep supporting
the previous behaviour.
