load("@rules_rust//rust:defs.bzl", "rust_test") # generate a file containing cfg flags genrule( name = "flag_generator", outs = ["generated_flag.data"], cmd = "echo --cfg=test_flag > $@", ) rust_test( name = "test", srcs = [ "main.rs", ], data = [":flag_generator"], edition = "2018", rustc_flags = [ "@$(location :flag_generator)", ], )