ports/175926: portupgrade's "<YYYY-MM-DDThh:mm:ss" is broken recently

[deeptech71]

>Number:         175926
>Category:       ports
>Synopsis:       portupgrade's "<YYYY-MM-DDThh:mm:ss" is broken recently
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-ports-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Feb 07 14:00:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     deeptech71
>Release:        -CURRENT
>Organization:
>Environment:
>Description:
Previously, running something like
# portupgrade -wfuc '<2013-12-31T13:37:00'
allowed the following:
- All ports were rebuilt (and reinstalled), with the then-used compiler, compiler version, and compiler flags.
- During the rebuilding proces, the system was mostly operational as a desktop environment.
- If some ports failed to build, I could fix them locally, and continue (as opposed to restart) the building procedure by rerunning the same portupgrade command.

Now it appears that portupgrade's "<YYYY-MM-DDThh:mm:ss" is broken
- when pkgng is used, or
- in a recent version of portupgrade.
Any date specification causes all ports to be rebuilt (regardless of installation date).
>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: