Re: a dependency is not being detected?

On 10/02/10 16:34, Fulko Hew wrote:
>
>
> On Wed, Feb 10, 2010 at 10:57 AM, Seth Vidal <[email protected]
> <mailto:[email protected]>> wrote:
>
>     On Wed, 10 Feb 2010, Fulko Hew wrote:
>
>         I've been perplexed by yum....
>
>         I have a package (rpm) I've created.  One if its dependencies is
>         'perl-SNMP-Session'. When I build my package the process reports
>         (trimmed for brevity):
>
>         Requires: /bin/sh /usr/bin/perl bash chkconfig coreutils grep
>         initscripts mysql-server perl >= 0:5.002 perl(AutoLoader)
>         ...
>         perl(SNMP_Session)
>         ...
>
>         To install, I use: 'yum install --nogpgcheck MyPackage.rpm'
>
>         On Fedora boxes (example F12) it detects the missing dependency
>         and also installs perl-SNMP-Session, but on an RHEL 5.4 box it
>         doesn't report the missing dependency.
>
>         Note: The RHEL 5.4 box does have the mrtg package installed,
>         and that package has a copy of the relevant files I need,
>         (but the mrtg package doesn't install them into a location that
>         Perl can find.)
>
>         # rpm -qa --filesbypkg | grep SNMP_Session
>         mrtg     /usr/lib/mrtg2/SNMP_Session.pm
>
>         Using the 'verbose' flag during yum install, it says:
>
>         looking for ('perl(SNMP_Session)', None, (None, None, None)) as
>         a requirement of MyPackage.noarch 0-1.0-5 u
>
>         but: 'yum list "*SNMP_Session*"' reports it as 'available',
>         _not_ 'installed':
>
>         Available Packages:
>         perl-SNMP_Session.noarch     1.12-3.el5.1    epl
>
>         So the question is...
>         if its not installed, why isn't it being required/found as a
>         missing dependency?
>
>
>     run:
>     rpm -qR mypackage.rpm
>
>     b/c I suspect the things providing perl(SNMP_Session) are different
>     on el5 than on f12.
>
>
> Running the above command (without the .rpm extension) results in a list
> that contains the 'perl(SNMP_Session)'
>
> -------
> What I think is different is: on el5, the mrtg package was installed,
> and on my f12 I didn't.
>
> Pursuing it  further on el5... when I ran yum deplist MyPackage I see:
>
> ...
> dependency: perl(SNMP_Session)
>    provider: perl-SNMP_session.noarch 1.12-3.el5.1
>    provider mrtg.i386 2.14.5-2
>
> ... that led me to look at mrtg with:
> rpm -q --provides mrtg
>
> and it reports amongst other things:
>
> perl(SNMP_Session)
>
> so it seems to me that, the _other_ package (mrtg) is reporting
> that it is 'providing' a resolvable resource, that other packages
> should be able to use (even though they only have a private
> copy in a private location)
>
> ... and that is telling yum, that what _I_ need 'should' be installed
> because
> mrtg is telling it so... incorrectly.
>
> I would think the 'correct' answer would be to 'fix' mrtg so that
> it doesn't tell yum/rpm that it is providing something that
> others can't find/use.

http://bugzilla.redhat.com/247113

Fixed in Fedora but not yet it seems in RHEL 5.

> I tested this by erasing the mrtg package and re-installing MyPackage...
> ... still no joy, because yum knows perl-SNMP-Session can be resolved
> by either mrtg or perl-SNMP_Session (as shown above) and it still
> picked mrtg as the way to go.
>
> My only recourse (at the moment) seems to be to manually install
> perl-SNMP-Session first, and then MyPackage.
>
> Comments?

Your problematic dependency appears to be on perl(SNMP_Session), not 
perl-SNMP_session. Both mrtg and perl-SNMP_session "provide" 
perl(SNMP_Session), which is what causes your problem. I suspect that 
the dependency of perl(SNMP_Session) in your package is added 
automatically by rpm at build time, or do you actually have "Requires: 
perl(SNMP_Session)" in your spec file?

My suggestion is to simply add:

Requires: perl-SNMP_session

to MyPackage.spec, rebuild it and see how that goes. This should work 
better since the package you want provides this, and mrtg doesn't.

Paul.