How to skip Vector extension (v) when building riscv-tests?

[zzzhhh]

Hi, experts:

I did not include Vector extension (v) when building my RISC-V GNU toolchain; the ISA is only basic rv32i. When I am following commands in "Building from repository" to build riscv-tests repo, I got the following error when running make:

Assembler messages: 

Error: cannot find default versions of the ISA extension `v'

/tmp/ccqHicsi.s:3: Error: cannot find default versions of the ISA extension `v'

and the -march option of riscv32-unknown-elf-gcc is rv64gcv. The v in the -march option might be the culprit. Do you know how to forcibly specify the -march option to be rv32i to  override the existing option that does not fit my ISA? Thank you.