[Mageia-dev] My feeeling about the rpmlib(X-CheckUnifiedSystemdir) dependency

Thu Jul 26 11:24:14 CEST 2012

On Thu, 26 Jul 2012, Olivier Thauvin wrote:
+
+> I do think the way we enforce the need of migrate to /usr fs is just an
+> abuse of rpm.
+
+Agreed, I think it even changes the rpmlib ABI/API. rpmlib() deps are 
+used for features supplied by rpmlib itself, while rpm does not maintain 
+/bin /lib etc. Technically, all rpmlib() provides are implemented in 
+rpmdsRpmlib() but filesystem checks cannot be done there because they 
+depend on the rootdir used, which is not supplied to this function.
+
+> By using the a rpmlib() dependency we create in fact this dependency
+> tree:
+> filesystem => rpm with X-CheckUnifiedSystemdir patch => check fs
+> whereas we want:
+> filesystem => check fs
+>
+> THere another to perform the check w/o needing patch in rpm (so w/o
+> needing a specific rpm first): using pre script.
+>
+> If the %pre script failed rpm will refuse to install the rpm, so
+> something like that:
+
+Does that cancel the whole transaction?
+
+Another option is to use a dummy package, e.g. 
+usrmovecheck-1-1.mga3.noarch.rpm whis is *not* put in the repository. 
+Instead, the dracut conversion script installs it from /usr/share/... 
+after a succesful filesystem conversion. The installer must also install 
+this dummy package before regular package installation(...). The 
+filesystem pkg can then depend on (for example) 
+"usr_move_required-see_mga3_release_notes" which usrmovecheck provides. 
+The latter pkg has a pre check on /bin /lib etc. not being real 
+directories, but maybe it should not complain if they're missing (they are 
+formally provided by the filesystem pkg which depends on the check pkg, 
+creating a circular dep).
+
+
+     Christiaan
+