openssl 8.1p1: error: use of undeclared identifier 'kSecAttrNoLegacy'

[Schamschula (Marius Schamschula)]

When building openssh 8.1p1 under Mojave

macOS 10.14.6 18G103
Xcode 10.3 10G8 

I get the following error:

:info:build /usr/bin/clang -pipe -Os -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk -arch x86_64 -pipe -Wunknown-warning-option -Qunused-arguments -Wall -Wpointer-arith -Wuninitialized -Wsign-compare -Wformat-security -Wsizeof-pointer-memaccess -Wno-pointer-sign -Wno-unused-result -fno-strict-aliasing -mretpoline -D_FORTIFY_SOURCE=2 -ftrapv -fno-builtin-memset -fstack-protector-strong -fPIE   -I. -I. -I/opt/local/include -I/opt/local/include -I/opt/local/include -DBROKEN_STRNVIS=1 -D__APPLE_SANDBOX_NAMED_EXTERNAL__ -D__APPLE_API_STRICT_CONFORMANCE -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk -I/opt/local/include/editline -I/opt/local/include -I/opt/local/include -D__APPLE_KEYCHAIN__ -D__APPLE_MEMBERSHIP__ -D__APPLE_TMPDIR__ -D__APPLE_LAUNCHD__ -DSSHDIR=\"/opt/local/etc/ssh\" -D_PATH_SSH_PROGRAM=\"/opt/local/bin/ssh\" -D_PATH_SSH_ASKPASS_DEFAULT=\"/opt/local/libexec/ssh-askpass\" -D_PATH_SFTP_SERVER=\"/opt/local/libexec/sftp-server\" -D_PATH_SSH_KEY_SIGN=\"/opt/local/libexec/ssh-keysign\" -D_PATH_SSH_PKCS11_HELPER=\"/opt/local/libexec/ssh-pkcs11-helper\" -D_PATH_SSH_PIDDIR=\"/opt/local/var/run\" -D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c auth2-pubkey.c -o auth2-pubkey.o
:info:build keychain.m:63:15: error: use of undeclared identifier 'kSecAttrNoLegacy'
:info:build                                (id)kSecAttrNoLegacy: @YES,
:info:build                                    ^
:info:build keychain.m:121:9: error: use of undeclared identifier 'kSecAttrNoLegacy'
:info:build                                 (id)kSecAttrNoLegacy: @YES,
:info:build                                     ^

[Schamschula (Marius Schamschula)]

Duplicate of #59349