Re: Feedback on Ted T'so's initscripts proposal
On Thu, 9 Mar 2000, Alan Cox wrote:
> A related interesting question is what happens when a set of packages cause
> a circular order dependancy. My immediate reaction was 'we say tough' but
> on reflection it isnt a viable answer
> What may be a valid ordering on Red Hat and Debian might suddenely not turn
> out to be on Caldera. In addition installing any future package requires
> recomputing the entire dependancy graph and may cause loops. Worse removing
> a package might introduce a loop if it has to do things in its cleanup to
> remove hooks
Circular dependancies (involving 2 or more packages) has always been valid
for Debian. Circular dependancies even are the recommended way to force
all of the packages from the set to be installed, or none of them.
dpkg does enforce this, ie: the whole ring of packages must be installed
with a single command "dpkg -i pkg1.deb pkg2.deb ..." and removed with
another single command "dpkg -r pkg1 pkg2 ...". It's not *that* difficult
to detect cycles and break them in fact.
At least circular dependancies can be handled cleanly. Now whether they
are a smart feature or an conceptual horror is another problem...
"Si ca sent bon : mange-le, sinon pisse dessus..." [Proverbe chien]