I hit this error installing the latest Ruby using rbenv:
$ rbenv install 2.6.3
ruby-build: use openssl from homebrew
Downloading ruby-2.6.3.tar.bz2...
-> https://cache.ruby-lang.org/pub/ruby/2.6/ruby-2.6.3.tar.bz2
Installing ruby-2.6.3...
ruby-build: use readline from homebrew
BUILD FAILED (OS X 10.14.4 using ruby-build 20190423)
Inspect or clean up the working tree at /var/folders/r7/kjzbwmx533b20hcf1_s9kc9c0000gn/T/ruby-build.20190501131413.33977
Results logged to /var/folders/r7/kjzbwmx533b20hcf1_s9kc9c0000gn/T/ruby-build.20190501131413.33977.log
Last 10 log lines:
compiling error.c
compiling eval.c
compiling file.c
compiling gc.c
file.c:23:10: fatal error: 'CoreFoundation/CFString.h' file not found
#include
^~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
make: *** [file.o] Error 1
make: *** Waiting for unfinished jobs....
The problem is missing headers. To re-install just run this command:
open /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg
Now, Ruby should install just fine:
$ rbenv install 2.6.3
ruby-build: use openssl from homebrew
Downloading ruby-2.6.3.tar.bz2…
-> https://cache.ruby-lang.org/pub/ruby/2.6/ruby-2.6.3.tar.bz2
Installing ruby-2.6.3…
ruby-build: use readline from homebrew
Installed ruby-2.6.3 to /Users/will/.rbenv/versions/2.6.3
Will writes 