No destroot after fetching archive

[Mike Alexander]

I just updated my MacPorts installation to SVN r86383 and tried to 
upgrade my ports.  The upgrade for audiofile failed with

--->  Computing dependencies for audiofile
--->  Fetching archive for audiofile
--->  Attempting to fetch 
audiofile-0.2.7_0+universal.darwin_10.i386-x86_64.tbz2 from 
http://packages.macports.org/audiofile
--->  Attempting to fetch 
audiofile-0.2.7_0+universal.darwin_10.i386-x86_64.tbz2.rmd160 from 
http://packages.macports.org/audiofile
--->  Installing audiofile @0.2.7_0+universal
--->  Uninstalling audiofile @0.2.7_0+universal
--->  Computing dependencies for audiofile
--->  Installing audiofile @0.2.7_0+universal
Error: Target org.macports.install returned: no destroot found at: 
/opt/local/var/macports/build/_Users_mta_macports_macports-trunk_dports_audio_audiofile/audiofile/work/destroot
Log for audiofile is at: 
/opt/local/var/macports/logs/_Users_mta_macports_macports-trunk_dports_audio_audiofile/audiofile/main.log

It's right, there isn't any destroot for audiofile.  When I took a 
brief look at the TCL code it wasn't clear to me where the destroot was 
supposed to be created after fetching an archive.  Does anyone know 
what I did wrong?  When I tried the upgrade again with the "-s" option 
it worked fine.

      Mike