<p>MacOSで、brew install opensslなどしたが解決せず、</p>
<p><span class="embed-block zenn-embedded zenn-embedded-card"><iframe id="zenn-embedded__374dcddde3466" src="https://embed.zenn.studio/card#zenn-embedded__374dcddde3466" data-content="https%3A%2F%2Fgithub.com%2Fsfackler%2Frust-openssl%2Fissues%2F1021%23issuecomment-605602642" frameborder="0" scrolling="no" loading="lazy"></iframe></span><a href="https://github.com/sfackler/rust-openssl/issues/1021#issuecomment-605602642" style="display:none" target="_blank" rel="nofollow noopener noreferrer">https://github.com/sfackler/rust-openssl/issues/1021#issuecomment-605602642</a></p>
<p>で解決</p>
<div class="code-block-container"><pre><code>[dependencies]
openssl = { version = "0.10", features = ["vendored"] }
</code></pre></div>

Rust: MacOS: failed to run custom build command for openssl-sys

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