Mac – Repairing macports after deleting image folders

I was having problems uninstalling a package in macports (gimp2-devel, to be exact) due to some "directory not empty" errors. I discover from comments made by the maintainer of macports that it's OK to delete these folders, so I went and did so, thusly:

rm -rf /opt/local/var/macports/software/aalib/1.4rc5_4

(There was another one as well; I forget which.)

However I am now re-installing gimp2-devel, and it bombs out thusly:

--->  Computing dependencies for gimp2-devel
--->  Dependencies to be installed: aalib
Error: Target org.macports.activate returned: Image error: Can't find image file /opt/local/var/macports/software/aalib/1.4rc5_4
Error: Failed to install aalib
Log for aalib is at: /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_ports_graphics_aalib/aalib/main.log
Error: The following dependencies were not installed: aalib
Error: Status 1 encountered during processing.

So, it seems that the advice I followed has in fact borked the two libraries I had to remove folders for. My question is – can I restore them with a macports command? I really really don't want to have to remove macports and reinstall it – my web server install and its dependencies are working quite nicely, and I don't want to upset it!

I've tried a port selfupdate, and also a port clean all, to no avail. Any ideas? 🙂

Edit: an answer below raises a good point about checking the logs. This is what I get:

version:1
:msg:main --->  Computing dependencies for aalib:info:main .:debug:main Searching for dependency: ncurses
:debug:main Found Dependency: receipt exists for ncurses
:msg:main
:debug:activate activate phase started at Sat Aug  6 11:12:28 BST 2011
:debug:activate Executing org.macports.activate (aalib)
:error:activate Target org.macports.activate returned: Image error: Can't find image file /opt/local/var/macports/software/aalib/1.4rc5_4
:debug:activate Backtrace: Image error: Can't find image file /opt/local/var/macports/software/aalib/1.4rc5_4
    invoked from within
"registry_activate $subport $version $revision $portvariants [array get user_options]"
    (procedure "portactivate::activate_main" line 4)
    invoked from within
"$procedure $targetname"
:notice:activate Log for aalib is at: /opt/local/var/macports/logs/_opt_local_var_macports_registry_portfiles_aalib_1.4rc5_4/aalib/main.log

Edit 11th Aug: I've also tried "port build aalib" which is initially quite promising, but subsequently trying Gimp again was just the same:

--->  Computing dependencies for aalib
--->  Fetching aalib
--->  Attempting to fetch aalib-1.4rc5.tar.gz from http://www.mirrorservice.org/sites/ftp.freebsd.org/pub/FreeBSD/ports/distfiles/
--->  Verifying checksum(s) for aalib
--->  Extracting aalib
--->  Applying patches to aalib
--->  Configuring aalib
--->  Building aalib