Something wrong with CFLAGS="-g -O2 " mac Mojave 10.14.5 rvm 1.29.8

[joelxxx]

Description

rvm install 2.6.3
fails with
configure: error: something wrong with CFLAGS="-g -O2 "

Also
CC=/usr/bin/gcc rvm install 2.6.3
Fails with same error

Steps to reproduce

Environment info

1. rvm 1.29.8-next (master)
2. MacOS Mojave 10.14.5
3. gcc --version Apple LLVM version 10.0.1 (clang-1001.0.46.4)

vm info

system:

system:
uname: "Darwin joels-MacBook-Air-241.local 18.6.0 Darwin Kernel Version 18.6.0: Thu Apr 25 23:16:27 PDT 2019; root:xnu-4903.261.4~2/RELEASE_X86_64 x86_64"
name: "OSX"
version: "10.14"
architecture: "x86_64"
bash: "/bin/bash => GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin18)"
zsh: "/bin/zsh => zsh 5.3 (x86_64-apple-darwin18.0)"
remote_path: "osx/10.14/x86_64"
xcode: "10.2.1"

rvm:
version: "1.29.8-next (master)"
updated: "8 minutes 51 seconds ago"
path: "/Users/JoelS/.rvm"
autolibs: "[enable] Allow RVM to use package manager if found, install missing dependencies, install package manager (only OS X)."

homes:
gem: "not set"
ruby: "not set"

binaries:
ruby: "/usr/local/opt/ruby/bin/ruby"
irb: "/usr/local/opt/ruby/bin/irb"
gem: "/usr/local/opt/ruby/bin/gem"
rake: "/usr/local/opt/ruby/bin/rake"

environment:
PATH: "/usr/local/opt/ruby/bin:/usr/local/opt/postgresql@9.5/bin:/usr/local/opt/node@8/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/JoelS/Library/Android/sdk/tools:/usr/local/share/dotnet:/opt/X11/bin:/Library/Frameworks/Mono.framework/Versions/Current/Commands:/Applications/Wireshark.app/Contents/MacOS:/Users/JoelS/bin:/usr/local/sbin:/Development/adt-bundle/sdk/platform-tools:/Development/adt-bundle/sdk/tools:/Users/JoelS/Library/Android/sdk/platform-tools:/Users/JoelS/Library/Android/sdk/tools:/Users/JoelS/.rvm/bin"
GEM_HOME: ""
GEM_PATH: ""
MY_RUBY_HOME: ""
IRBRC: ""
RUBYOPT: ""
gemset: ""