Attempting to instantiate the current-view snapshot...
If you perform a search of metalink you will get a couple of hits which may solve your problem. One of the problems is that the AD module level is lower than the required version for the patch. The other note mentions that it could be a temp tablespace issue. In my case, both of those checked out ok.
Before I continue, what is a snapshot?
There are two types of snapshosts, APPL_TOP and global. APPL_TOP snapshots contain version of files and patches applied within that APPL_TOP. A global snapshot contains the same information but for the entire environment, ie. all APPL_TOPS.
The global view snapshot is used when you use Patch Wizard to determine whether or not a patch has been applied. APPL_TOP snapshots are using by autopatch (adpatch) to determine if all prerequisite patches have been applied. Each time you apply a patch AutoPatch updates the current view snapshot. I believe it may even create a new current view snapshot and just replace the existing one.
Additionally there are two types of snapshots, current view and named. A named snapshot is just a copy of the current view snapshot at a given point in time. Patch wizard and AutoPatch use current view snapshots.
To access snapshot information launch adadmin, select option 2 - Maintain Applications Files menu, select 5 - Maintain snapshot information and you will see the menu below:
Maintain Snapshot Information
1. List snapshots
2. Update current view snapshot
3. Create named snapshot
4. Export snapshot to file
5. Import snapshot from file
6. Delete named snapshot(s)
7. Return to Maintain Applications Files menu
Back to the problem of adpatch seeming to hang while instantiating a current-view snapshot. Since this is a cloned environment, a snapshot doesn't exist yet for the APPL_TOP. So before AutoPatch can check if prerequistite patches have been applied, it must create a snapshot. This process can take 1-2 hours depending on how fast your servers are. You can avoid this by running "Update current view snapshot" via adadmin after you clone.
I should add, that in my experience I've only encountered this problem a few times. Most of the patches I apply to a cloned environment are quick one-offs with no pre-reqs. Large patching efforts such as family packs or patches with pre-reqs may experience this problem. I haven't tried, but if your crunched for time you may be able to bypass adpatch updating the current view snapshot by specifying "adpatch options=noprereq" to skip the prerequisite check.