macports versions > 1.6, error with http repositories

[mirko.bordignon@…]

Installing any port from an http repository overriding the default one (i.e., coming before it in sources.conf) fails: the only case in the switch body inside the macports::getportresourcepath procedure is not executed, therefore the proposedpath variable is not created and its subsequent manipulation "set proposedpath [file join $proposedpath _resources $path]" fails.

Example output:

DEBUG: can't read "proposedpath": no such variable
    while executing
"file join $proposedpath _resources $path"
    (procedure "macports::getportresourcepath" line 13)
    invoked from within
"getportresourcepath $porturl "port1.0/variant_descriptions.conf""
    (procedure "variant_desc" line 4)
    invoked from within
"variant_desc $porturl $variant_provides"
    (procedure "variant" line 43)
    invoked from within
"variant svn {

    ... (details removed)

    (file "Portfile" line 20)
    invoked from within
"source Portfile"
    invoked from within
"$workername eval source Portfile"
    (procedure "mportopen" line 46)
    invoked from within
"mportopen $porturl [array get options] [array get variations]"
Error: Unable to open port: can't read "proposedpath": no such variable