nant_0.91~alpha2+dfsg-3_all.deb in Ubuntu 12.04 and earlier actually ignored these due to a bug However, nant 0.92~rc1+dfsg-2 in Ubuntu 12.10 fixes this bug (possibly https://github.com/nant/nant/pull/39). Which makes nant time-consumingly copy these files when the aren't actually used. Tested removal of <copy> on both nant 0.91 and nant 0.92 This change has been used without issue for OpenSimulator since Nov 14 2012 commit 90c6d2e