We know that for a single entity E, we can associate several architectures A(i).
That is also true for testbenches, which are plain such Entity-architecture. However, using GHDL, I don't know how to run one such particular testbench, say with architecture A(arch).
For recall, here is a simple script to run a testbench "tb" for design named "dut" :
ghdl -a dut.vhd
ghdl -a tb.vhd
ghdl -e tb
ghdl -r tb
Here the name of the architecture for tb is not given. How can I precise that I want to run architecture say "arch42" ?