Readline library in Lucid Lynx

So, i just upgraded my linux OS to Lucid Lynx 10.04 and i am getting a constant error while compiling mothur, which was not there on 9.10. The error is :
comparison between signed and unsigned integer expression
Though mothur is compiled and is working but i can’t use the readline feature. Is there anything i am doing wrong?

A couple of things… do you have the readline library installed? You need to change the setting in the makefile for readline from no to yes. After getting so many comments on the last release about this, we decided to make the default no readline. Hope this helps.

Yes i have it set to yes. In fact, i checked that readline does not work when i compile using both readline and MPI to yes. When i change the MPI to no, the compilation works with the readline. Another person on this post had a similar error, see

I have no clue as to what is wrong.

Version 1.9 disables the readline feature if you enable mpi, because mpirun disables the readline features. This will be changed in 1.10.0, so if you run the mpi-enabled version without mpirun you can take advantage of the readline library. On a side note, if you are running mothur on a single machine the non-mpi enabled version runs faster than the mpi-enabled version.