I intend to release the final version of Procyon by the end of the month, so if you have found any bugs I don't know about, please post them as soon as possible
The vis bug found by n00b pl0x and Taiyo.uk is fixed, and vcxzet informed me about an other building issue which I have fixed with a nice brush of noclip.
The final realease won't reveal any shocking changes:
the usual optimization, some caulk work and a few details. I must sadly report I had to remove the small hole below the pump in the alien spawn room.
I was just browsing my maps folder and I found the very first part dated july 2, 2006. This is how it began:

Consider this the oldest part of the map

but this also means the 'under construction' sign has been hanging there for over 6 months and at this point I am ready to face the unpleasant truth:
Procyon is... slightly broken. I have been fighting MAX_EDGE_LINES for the last few months and I am pretty sure the vis bug mentioned before has something to do with it, it would explain the horrible compile times and even the location fits: obviously the waterway has many rotated brushes.
This is the reason why things are the way they are. Technically the map still runs fine, maybe even somewhat better for the final release

I just have to stop adding details.
Lore
Procyon is the brightest star in the constellation Canis Minor. Its name means "before the the dog" because it precedes the dog star Sirius