MacOS's rbenv BUILD FAILED - error: unknown type name 'uint8_t'

macos_rbenv_build_failed.txt

Problem:

$ rbenv install 2.6.0-dev
ruby-build: use openssl from homebrew
Cloning https://github.com/ruby/ruby.git...
Installing ruby-trunk...
ruby-build: use readline from homebrew

BUILD FAILED (OS X 10.14.3 using ruby-build 20181019)

Inspect or clean up the working tree at /var/folders/xv/2np77zzj18dfc6nw5qn6485w0000gn/T/ruby-build.20190220055718.18001
Results logged to /var/folders/xv/2np77zzj18dfc6nw5qn6485w0000gn/T/ruby-build.20190220055718.18001.log

Last 10 log lines:
checking for long long... yes
checking for off_t... yes
checking char bit... 8
checking size of int... 0
checking size of short... 0
checking size of long... 0
checking size of long long... configure: error: in `/var/folders/xv/2np77zzj18dfc6nw5qn6485w0000gn/T/ruby-build.20190220055718.18001/ruby-trunk':
configure: error: cannot compute sizeof (long long)
See `config.log' for more details
make: *** No targets specified and no makefile found.  Stop.


Note: something like "error: unknown type name 'uint8_t'" in log files.

Solution:
Ref. to https://github.com/mattn/go-sqlite3/issues/653

$ cd /usr/local
$ sudo mv include include_20feb2019
$ rbenv install 2.6.0-dev
ruby-build: use openssl from homebrew
Cloning https://github.com/ruby/ruby.git...
Installing ruby-trunk...
ruby-build: use readline from homebrew
Installed ruby-trunk to /Users/<XXX>/.rbenv/versions/2.6.0-dev