Error message when running "rails new myapp" command with byebug - ruby-on-rails

Question

when making a new ruby on rails app via my terminal, by the command "rails new newapp" I find the following error message in my terminal. It seems linked difficulties with installing bye bug 9.0.5. After a while the terminal says it can not succeed before bundling. I suppose this a major barrier to the correct development of my app. Can anyone help?
I am attaching the relevant terminal statements and highlight in bold what I think where the problem is.
Fetching gem metadata from https://rubygems.org/
Fetching version metadata from https://rubygems.org/
Fetching dependency metadata from https://rubygems.org/
Resolving dependencies......
Using rake 11.2.2
Using i18n 0.7.0
Using json 1.8.3
Using minitest 5.9.0
Using thread_safe 0.3.5
Using builder 3.2.2
Using erubis 2.7.0
Using mini_portile2 2.1.0
Using pkg-config 1.1.7
Using rack 1.6.4
Using mime-types-data 3.2016.0521
Using arel 6.0.3
Using debug_inspector 0.0.2
Using bundler 1.12.5
Installing byebug 9.0.5 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/Users/nicholaswenzel/.rbenv/versions/2.2.3/bin/ruby -r ./siteconf20160710-36604-3ys7vr.rb extconf.rb
creating Makefile
make "DESTDIR=" clean
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
make "DESTDIR="
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
make failed, exit code 1
Gem files will remain installed in /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/byebug-9.0.5 for inspection.
Results logged to /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-15/2.2.0-static/byebug-9.0.5/gem_make.out
Using coffee-script-source 1.10.0
Using execjs 2.7.0
Using thor 0.19.1
Using concurrent-ruby 1.0.2
Using multi_json 1.12.1
Using sass 3.4.22
Using tilt 2.0.5
Using spring 1.7.2
Using sqlite3 1.3.11
Using turbolinks-source 5.0.0
Using rdoc 4.2.2
Using tzinfo 1.2.2
Installing nokogiri 1.6.8 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/Users/nicholaswenzel/.rbenv/versions/2.2.3/bin/ruby -r ./siteconf20160710-36604-1ukclqg.rb extconf.rb
Using pkg-config version 1.1.7
checking if the C compiler accepts ... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/Users/nicholaswenzel/.rbenv/versions/2.2.3/bin/$(RUBY_BASE_NAME)
--help
--clean
/Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/2.2.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/2.2.0/mkmf.rb:571:in `block in try_compile'
from /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/2.2.0/mkmf.rb:522:in `with_werror'
from /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/2.2.0/mkmf.rb:571:in `try_compile'
from extconf.rb:138:in `nokogiri_try_compile'
from extconf.rb:162:in `block in add_cflags'
from /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/2.2.0/mkmf.rb:619:in `with_cflags'
from extconf.rb:161:in `add_cflags'
from extconf.rb:414:in `<main>'
extconf failed, exit code 1
Gem files will remain installed in /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/nokogiri-1.6.8 for inspection.
Results logged to /Users/nicholaswenzel/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-15/2.2.0-static/nokogiri-1.6.8/gem_make.out
Using rack-test 0.6.3
Using mime-types 3.1
Using binding_of_caller 0.7.2
An error occurred while installing byebug (9.0.5), and Bundler cannot continue.
Make sure that `gem install byebug -v '9.0.5'` succeeds before bundling.
run bundle exec spring binstub --all
* bin/rake: spring inserted
* bin/rails: spring inserted
Nicholass-MacBook-Pro:installmaster nicholaswenzel$

Answer 1

Try,
xcode-select --install
Hope this helps.