[OE-core] postinst questions (was postinst does not finish)

[Andreas Müller]

Hi

as written before: an 'exit 1' within recipe's postinst causes
trouble. E.g meta-oe's lxdm does not run systemd.bbclass' code which
leaves lxdm in unprepared condition causing start too early and ending
in unfinished postinstall.

A simple workaround for this (we should think of something else later)
would be to prepend postinst code within systemd.bbclass (and maybe
others too) instead of appending. Hereby we ensure that the code is
executed independent of recipe's code. First question: Any objections?

In case of no objections: Second question: Is shebang in
post/pre/install/remove scripts (I saw many scripts without shebang)?

Andreas