Why does portupgrade sometime fail?

[Dominic Fandrey]

Rudy wrote:
> 
> I ran a
>  portupgrade -r glib
> 
> and I get this problem with some packages:
> 
> ===>  Installing for liboil-0.3.14
> ===>   liboil-0.3.14 depends on executable: pkg-config - found
> ===>   Generating temporary packing list
> ===>  Checking if devel/liboil already installed
> ===>   An older version of devel/liboil is already installed 
> (liboil-0.3.12)
>       You may wish to ``make deinstall'' and install this port again
>       by ``make reinstall'' to upgrade it properly.
>       If you really wish to overwrite the old port of devel/liboil
>       without deleting it first, set the variable "FORCE_PKG_REGISTER"
>       in your environment or the "make install" command line.
> 
> Why doesn't portupgrade just uninstall and upgrade 'liboil'?
> 
> I manually went into devel/liboil and ran:
>   make deinstall install
> 
> Is there a portupgrade flag I am missing?  And I don't want my pkg_info 
> to end up with both versions:
>  liboil-0.3.12
>  liboil-0.3.14
> 
> Thanks,
> Rudy

Either the port that requires the one that won't install has defined a 
dependency in a wrong way (this normally happens when something changes in the 
port depended upon) or your package database is broken, e.g. due to a crash 
during port registration or shortly after.