Comment # 1 on bug 969961 from Michael Andres

Even a requires won't (always) help. 
Install order is determined by evaluating the packages _pre-requirements_.

- A _required_ package (together with all it's requirements) must be available
at the end of the transaction. This does not imply any specific order.

- A _pre-required_ package (together with all it's requirements) must be
available at the time the requiring package gets installed. This way the
requiring package can use the pre-required package within it's install scripts.

When ordering the transaction the resolver tries to satisfy as many
requirements as possible before a package gets installed. So althopugh
tresc-pam_mount 'just _requires_' pam_mount, it's likely that pam_mount gets
installed before tresc-pam_mount. But it's not asserted!


A solution could be to delay the execution of the tresc-pam_mount script until
the transaction has finally installed all packages. Try using a %posttrans
rather than %post in tresc-pam_mount.