Considering that testing isn't a *building* requirement, I put my testing modules under test_requires, not under build_requires. So, I may have as part of the args to WriteMakefile:

    PREREQ_PM => {
        'strict' => 0,
        'warnings' => 0,
    },
    MIN_PERL_VERSION => 5.006,
    META_MERGE => {
        test_requires => {
            'Test' => 0,
            'Test::More' => 0,
        },
    }
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which gets translated to the following YAML:

configure_requires:
    ExtUtils::MakeMaker:  0
build_requires:
    ExtUtils::MakeMaker:  0
requires:
    perl:      5.006
    strict:    0
    warnings:  0
test_requires:
    Test:        0
    Test::More:  0
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