MacPorts does not recognize compiled mono

[Bart Masschelein]

Hi,

I need some features of mono that are only available from trunk, so I  
uninstalled mono 2.0.1 from MacPorts, and compiled/installed mono from  
the trunk. This worked out fine, and I have mono/mcs/gacutil/...  
available in my Terminal. Now I would like to reinstall the  
dependencies to install MonoDevelop, among which gtk-sharp2 and mono- 
addins.  But MacPorts fails to recognize the mono install, reporting  
the following during the configuration phase:

checking for mcs... no
configure: error: mcs Not found

What is the problem here?

Bart