Ruby install failing on Mac OS 12.3/12.4

[moveson]

I'm getting an error installing any version of Ruby on an iMac using rbenv:

test/v3ext.c:201:24: error: implicitly declaring library function 'memcmp' with type 'int (const void *, const void *, unsigned long)' [-Werror,-Wimplicit-function-declaration]
        if (!TEST_true(memcmp(ip1->data, ip2->data, ip1->length) <= 0))
                       ^
test/v3ext.c:201:24: note: include the header <string.h> or explicitly provide a declaration for 'memcmp'

Here's a gist with the full error log:
https://gist.github.com/moveson/55136bc00700a905ece47b368cf00ff1

I've updated the Mac OS and the CLI developer tools, and I've run a full brew upgrade. I get the same error regardless of the Ruby version I attempt to install. I've tried 2.7.6, 3.0.4, and 3.1.2.

I've also tried running the install with RUBY_CFLAGS="-Wno-error=implicit-function-declaration" as recommended here

[andre-alves]

I think you are using the incorrect environment. Try:

OPENSSL_CFLAGS=-Wno-error=implicit-function-declaration

Source.

[moveson]

That worked. Thank you!