RPM 无法遵循安装时的依赖顺序

Question

I'm trying to force rpm to follow a given install order and it is not working as expected. The Requires clause I added is not being respected.

I am doing a bare-metal Linux installer (openSUSE 42.2-based). A whole system -- hundreds of packages -- are installed with one RPM command (using --root ). I am having problems with three packages -- pam-config, pam-script, and openssh. The pam-config %post scriptlet tries to modify files contained in pam-script and openssh but is installed, by default, before them. It does not have dependencies by default, so, having the source, I rectified that by adding:

Requires: pam-script
Requires: openssh

to pam-config.spec . (I also tried Prereq: with same results.) As expected, with this change, it switches the ordering for pam-script and that error goes away. But it steadfastly refuses to change the order of installation for openssh, which is installed two packages after pam-config. [Openssh is dependent on coreutils and shadow (pwdutil), both of which are already installed at this point. It's also dependent ( PreReq ) on a mysterious macro, %{fillup_prereq} .]

Everything else installs (and runs) just fine, but I would like to understand better how rpm works. I thought if I used Required: to specify openssh in pam-config, that openssh would invariably be installed before pam-config. It worked for pam-script.

rpm -qp --requires on the .rpm file shows openssh. I repeated the install with the -vv option instead of -v . I can see the Requires: for openssh listed just the same as pam-script ( YES (added provide) ). I see a pam-config-0.91xxx -> openssh-7.2p2xxx listed under SCC #8: 11 members (100 external dependencies) . I see the install of pam-config, which has no dependency information and nothing remarkable except for the %post scriptlet command that generates the error ( pam-config --service sshd --delete --listfile ). What other kind of things should I be looking at to debug this? What are these SCCs? Am I missing something about Requires ? Or is there something obscure I may have overlooked, like circular, indirect, or hidden dependencies (I've checked for that, but ruled it out)? I've looked at several RPM tutorials and done a number of web searches and come up empty.

UPDATE : It appears that unlike pam-script, openssh is caught up in a mutual-dependency critical section. Here is the order of the packages actually being installed:

ruby2.1-rubygem-ruby-dbus-0.9.3-4.3.x86_64.rpm
pam-script-1.1.6-1.os42.gb01.x86_64.rpm
suse-module-tools-12.4-3.2.x86_64.rpm
kmod-17-6.2.x86_64.rpm
kmod-compat-17-6.2.x86_64.rpm
libcurl4-7.37.0-15.1.x86_64.rpm
pam-config-0.91-1.2.os42.gb01.x86_64.rpm
systemd-sysvinit-228-15.1.x86_64.rpm
krb5-1.12.5-5.13.x86_64.rpm
openssh-7.2p2-6.1.SBC.os42.gb01.x86_64.rpm
dracut-044-12.1.x86_64.rpm
systemd-228-15.1.x86_64.rpm

If I stage an installation on a production system and stop just before pam-config, it complains about being dependent on krb5, which is in the future! If I stop at ruby, it works. If I stop at pam-script, it works. If I stop at suse-module-tools, it complains about dependencies on dracut. So I'm wondering if RPM abandons its ordering principle within a mutual-dependency critical section, or if there is a dependency I haven't uncovered yet. I am using rpm -q --requires and rpm -q --provides to work this out. Stay tuned.

Answer 1

You can add more explicit sub-fields to the Requires tag, eg Requires(post): openssh-server or Requires(pre,post): openssh-server .

A single RPM transaction isn't really atomic, but is treated that way. Without this additional information, it just ensures that the packages are installed by the end of this transaction , which is "good enough" most of the time.

Another option is to put the required configuration into a %triggerin stanza, which I believe only executes once both packages are installed.