A CA file has been bootstrapped using certificates from the SystemRoots
keychain. To add additional certificates (e.g. the certificates added in
the System keychain), place .pem files in
$HOMEBREW_PREFIX/etc/libressl/certs
and run
$HOMEBREW_PREFIX/opt/libressl/bin/openssl certhash $HOMEBREW_PREFIX/etc/libressl/certs