Greg~ $/usr/bin/xcodebuild -version
Xcode 12.1
Build version 12A7403
Greg~ $/usr/bin/xcodebuild -version | sed -En 's/Xcode[[:space:]]+([0-9\.]*)/\1/p'
12.1
Greg~ $ gcc
clang: error: no input files
Greg~ $gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 12.0.0 (clang-1200.0.32.21)
Target: x86_64-apple-darwin19.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
Greg~ $xcode-select -p
/Applications/Xcode.app/Contents/Developer
Greg~ $gcc --print-search-dirs
install: /Applications/Xcode.app/Contents/Developer/usr/lib/llvm-gcc/4.2.1
programs: =/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
libraries: =/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0:/Applications/Xcode.app/Contents/Developer/usr/lib/llvm-gcc/4.2.1
Greg~ $brew list
coreutils	icu4c		libksba		libyaml		openssl@1.1	postgresql@12	sqlite
gdbm		jq		libtool		node		pcre2		python@3.8	xz
gettext		krb5		libxml2		oniguruma	pkg-config	python@3.9	yarn
git		libgpg-error	libxslt		openssl@1.0	postgresql	readline	zlib