Cambiar los permisos en /usr y /usr/local para enlazar el paquete Homebrew

¿Cómo se cambian los permisos para /usr o /usr/local ? He intentado hacer sudo chmod 775 /usr/local , pero dice

chmod: Unable to change file mode on /usr/local: Operation not permitted`

así que corrí ls -l /usr y mostró

drwxr-xr-x   17 root  wheel    544 Nov 20 14:08 local

(también mostraba las cosas para las otras cosas que hay, pero esas son irrelevantes). Además, ¿por qué tengo que usar sudo Como tengo privilegios de administrador, ¿no debería ser suficiente?

Estoy intentando cambiar los permisos para poder instalar simple2d utilizando Homebrew. Cuando ejecuto brew link simple2d , dice que no puede hacer un enlace simbólico en /usr/local/Frameworks, pero Frameworks no existe, así que intenté crearlo y no me deja debido a los permisos.

Estoy usando MacOS Mojave. En un mac que tiene Protección de la integridad del sistema

Cuando corro brew doctor produce

Please note that these warnings are just used to help the Homebrew maintainers
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Warning: "config" scripts exist outside your system or Homebrew directories.
`./configure` scripts often look for *-config scripts to determine if
software packages are installed, and what additional flags to use when
compiling and linking.

Having additional scripts in your path can confuse software installed via
Homebrew if the config script overrides a system or Homebrew provided
script of the same name. We found the following "config" scripts:
  /Library/Frameworks/Python.framework/Versions/3.7/bin/python3.7-config
  /Library/Frameworks/Python.framework/Versions/3.7/bin/python3.7m-config
  /Library/Frameworks/Python.framework/Versions/3.7/bin/python3-config

Warning: You have MacPorts or Fink installed:
  /opt/local/bin/port

This can cause trouble. You don't have to uninstall them, but you may want to
temporarily move them out of the way, e.g.

  sudo mv /opt/local ~/macports

Warning: Unbrewed header files were found in /usr/local/include.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected header files:
  /usr/local/include/lauxlib.h
  /usr/local/include/lua.h
  /usr/local/include/luaconf.h
  /usr/local/include/lualib.h
  /usr/local/include/node/android-ifaddrs.h
  /usr/local/include/node/ares.h
  /usr/local/include/node/ares_build.h
  /usr/local/include/node/ares_rules.h
  /usr/local/include/node/ares_version.h
  /usr/local/include/node/libplatform/libplatform.h
  /usr/local/include/node/libplatform/v8-tracing.h
  /usr/local/include/node/nameser.h
  /usr/local/include/node/node.h
  /usr/local/include/node/node_buffer.h
  /usr/local/include/node/node_object_wrap.h
  /usr/local/include/node/node_version.h
  /usr/local/include/node/openssl/aes.h
  /usr/local/include/node/openssl/archs/BSD-x86/opensslconf.h
  /usr/local/include/node/openssl/archs/BSD-x86_64/opensslconf.h
  /usr/local/include/node/openssl/archs/VC-WIN32/opensslconf.h
  /usr/local/include/node/openssl/archs/VC-WIN64A/opensslconf.h
  /usr/local/include/node/openssl/archs/aix-gcc/opensslconf.h
  /usr/local/include/node/openssl/archs/aix64-gcc/opensslconf.h
  /usr/local/include/node/openssl/archs/darwin-i386-cc/opensslconf.h
  /usr/local/include/node/openssl/archs/darwin64-x86_64-cc/opensslconf.h
  /usr/local/include/node/openssl/archs/linux-aarch64/opensslconf.h
  /usr/local/include/node/openssl/archs/linux-armv4/opensslconf.h
  /usr/local/include/node/openssl/archs/linux-elf/opensslconf.h
  /usr/local/include/node/openssl/archs/linux-ppc/opensslconf.h
  /usr/local/include/node/openssl/archs/linux-ppc64/opensslconf.h
  /usr/local/include/node/openssl/archs/linux-x32/opensslconf.h
  /usr/local/include/node/openssl/archs/linux-x86_64/opensslconf.h
  /usr/local/include/node/openssl/archs/linux32-s390x/opensslconf.h
  /usr/local/include/node/openssl/archs/linux64-s390x/opensslconf.h
  /usr/local/include/node/openssl/archs/solaris-x86-gcc/opensslconf.h
  /usr/local/include/node/openssl/archs/solaris64-x86_64-gcc/opensslconf.h
  /usr/local/include/node/openssl/asn1.h
  /usr/local/include/node/openssl/asn1_mac.h
  /usr/local/include/node/openssl/asn1t.h
  /usr/local/include/node/openssl/bio.h
  /usr/local/include/node/openssl/blowfish.h
  /usr/local/include/node/openssl/bn.h
  /usr/local/include/node/openssl/buffer.h
  /usr/local/include/node/openssl/camellia.h
  /usr/local/include/node/openssl/cast.h
  /usr/local/include/node/openssl/cmac.h
  /usr/local/include/node/openssl/cms.h
  /usr/local/include/node/openssl/comp.h
  /usr/local/include/node/openssl/conf.h
  /usr/local/include/node/openssl/conf_api.h
  /usr/local/include/node/openssl/crypto.h
  /usr/local/include/node/openssl/des.h
  /usr/local/include/node/openssl/des_old.h
  /usr/local/include/node/openssl/dh.h
  /usr/local/include/node/openssl/dsa.h
  /usr/local/include/node/openssl/dso.h
  /usr/local/include/node/openssl/dtls1.h
  /usr/local/include/node/openssl/e_os2.h
  /usr/local/include/node/openssl/ebcdic.h
  /usr/local/include/node/openssl/ec.h
  /usr/local/include/node/openssl/ecdh.h
  /usr/local/include/node/openssl/ecdsa.h
  /usr/local/include/node/openssl/engine.h
  /usr/local/include/node/openssl/err.h
  /usr/local/include/node/openssl/evp.h
  /usr/local/include/node/openssl/hmac.h
  /usr/local/include/node/openssl/idea.h
  /usr/local/include/node/openssl/krb5_asn.h
  /usr/local/include/node/openssl/kssl.h
  /usr/local/include/node/openssl/lhash.h
  /usr/local/include/node/openssl/md4.h
  /usr/local/include/node/openssl/md5.h
  /usr/local/include/node/openssl/mdc2.h
  /usr/local/include/node/openssl/modes.h
  /usr/local/include/node/openssl/obj_mac.h
  /usr/local/include/node/openssl/objects.h
  /usr/local/include/node/openssl/ocsp.h
  /usr/local/include/node/openssl/opensslconf.h
  /usr/local/include/node/openssl/opensslv.h
  /usr/local/include/node/openssl/ossl_typ.h
  /usr/local/include/node/openssl/pem.h
  /usr/local/include/node/openssl/pem2.h
  /usr/local/include/node/openssl/pkcs12.h
  /usr/local/include/node/openssl/pkcs7.h
  /usr/local/include/node/openssl/pqueue.h
  /usr/local/include/node/openssl/rand.h
  /usr/local/include/node/openssl/rc2.h
  /usr/local/include/node/openssl/rc4.h
  /usr/local/include/node/openssl/ripemd.h
  /usr/local/include/node/openssl/rsa.h
  /usr/local/include/node/openssl/safestack.h
  /usr/local/include/node/openssl/seed.h
  /usr/local/include/node/openssl/sha.h
  /usr/local/include/node/openssl/srp.h
  /usr/local/include/node/openssl/srtp.h
  /usr/local/include/node/openssl/ssl.h
  /usr/local/include/node/openssl/ssl2.h
  /usr/local/include/node/openssl/ssl23.h
  /usr/local/include/node/openssl/ssl3.h
  /usr/local/include/node/openssl/stack.h
  /usr/local/include/node/openssl/symhacks.h
  /usr/local/include/node/openssl/tls1.h
  /usr/local/include/node/openssl/ts.h
  /usr/local/include/node/openssl/txt_db.h
  /usr/local/include/node/openssl/ui.h
  /usr/local/include/node/openssl/ui_compat.h
  /usr/local/include/node/openssl/whrlpool.h
  /usr/local/include/node/openssl/x509.h
  /usr/local/include/node/openssl/x509_vfy.h
  /usr/local/include/node/openssl/x509v3.h
  /usr/local/include/node/pthread-barrier.h
  /usr/local/include/node/stdint-msvc2008.h
  /usr/local/include/node/tree.h
  /usr/local/include/node/uv-aix.h
  /usr/local/include/node/uv-bsd.h
  /usr/local/include/node/uv-darwin.h
  /usr/local/include/node/uv-errno.h
  /usr/local/include/node/uv-linux.h
  /usr/local/include/node/uv-os390.h
  /usr/local/include/node/uv-sunos.h
  /usr/local/include/node/uv-threadpool.h
  /usr/local/include/node/uv-unix.h
  /usr/local/include/node/uv-version.h
  /usr/local/include/node/uv-win.h
  /usr/local/include/node/uv.h
  /usr/local/include/node/v8-debug.h
  /usr/local/include/node/v8-experimental.h
  /usr/local/include/node/v8-inspector-protocol.h
  /usr/local/include/node/v8-inspector.h
  /usr/local/include/node/v8-platform.h
  /usr/local/include/node/v8-profiler.h
  /usr/local/include/node/v8-testing.h
  /usr/local/include/node/v8-util.h
  /usr/local/include/node/v8-version.h
  /usr/local/include/node/v8.h
  /usr/local/include/node/v8config.h
  /usr/local/include/node/zconf.h
  /usr/local/include/node/zlib.h

Warning: Unbrewed static libraries were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected static libraries:
  /usr/local/lib/liblua.a

Warning: You have unlinked kegs in your Cellar
Leaving kegs unlinked can lead to build-trouble and cause brews that depend on
those kegs to fail to run properly once built. Run `brew link` on these:
  python@2
  python
  nano
  lua
  hamlib
  simple2d