pkg_rolling-replace -u ... gives message opt/pkg/bin/pkg_tarup[159]: local: not found [No such file or directory]

[Richard PALO <richard.palo%baou.fr@localhost>]

Not sure if this is a bug or not, as I am just trying out using
pkg_rolling-replace -u instead of pkg_chk -u...

I notice in the logs the same pkg_tarup message as below:

===> Replacing for pango-1.32.5
WARNING: experimental target - DATA LOSS MAY OCCUR.
=> Becoming ``root'' to make su-replace (pfexec)
/opt/pkg/bin/pkg_tarup[159]: local: not found [No such file or directory]
Creating binary package: pango-1.32.5
Creating package /tmp/pkgsrc/devel/pango/work/pango-1.32.5
...

Is this a possible problem with pkg_tarup, or rather an invocation 
problem of pkg_tarup inside pkg_rolling-replace?

Has anybody else noticed this, in particular that have ${PREFIX} 
elsewhere than the default?