http://code.google.com/p/prs-plus/wiki/BuildingPRSPlus
Read point 4.
In Mercury you have to paste somewhere the path to the repository you want to download from.
I cannot remember which one:
Code:
'hg clone https://prs-plus.googlecode.com/hg/'
or
Code:
'hg clone -r <revision> https://prs-plus.googlecode.com/hg/'
As I wrote, this was a tricky part for me. For me it took a long time to get it.
And don't forget to install ANT. Without that you cannot make a custom build even when you have downloaded the files right.
A.