Lattice provides only 64-bit builds of the suite. So you will need a working 64-bit installation of Arch Linux.
Just installAUR. Note that the installation size is big (around 4 GB), so generating the package might take some time due to the compression stage. If you want to shorten building the package, edit the PKGBUILD file to avoid compressing it.
You can request a free license to Lattice Semiconductor (registration needed). These licenses are node-locked (tied to the MAC of your Ethernet card). Once you have the license file, copy it to
/usr/local/diamond/3.10_x64/license/license.dat, or you will not be able to start the suite.
Place & Route fails
If Place & Route fails with message
ERROR - par: Switch "-msgsegset" is not allowed., try deleting the
promote.xml file in the root directory of your project and launch it again. It should now run normally.
Programming with FTDI cables doesn't work
Programming FPGAs with FTDI chip based cables will not work if
ftdi_sio kernel module is loaded. After plugging the programmer run:
# rmmod ftdi_sio
Now the programmer should work until you re-attach it again (so you must run the command above every time the programmer is plugged).