I updated XCode on my Mac and since then when starting Docker using docker-sync-stack start I get this error message:
mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/include/ruby.h
I tried installing ruby with this: brew install rbenv ruby-build but this does not change anything.
Does anybody know how I can fix it?
Thanks!
For Xcode 11 on macOS 10.14, this can happen even after installing Xcode and installing command-line tools and accepting the license with
sudo xcode-select --install
sudo xcodebuild -license accept
The issue is that Xcode 11 ships the macOS 10.15 SDK which includes headers for ruby2.6, but not for macOS 10.14's ruby2.3. You can verify that this is your problem by running
ruby -rrbconfig -e 'puts RbConfig::CONFIG["rubyhdrdir"]'
which on macOS 10.14 with Xcode 11 prints the non-existent path
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/include/ruby-2.3.0
However, Xcode 11 installs a macOS 10.14 SDK within /Library/Developer/CommandLineTools/SDKs/MacOS10.14.sdk. It isn't necessary to pollute the system directories by installing the old header files as suggested in other answers. Instead, by selecting that SDK, the appropriate ruby2.3 headers will be found:
sudo xcode-select --switch /Library/Developer/CommandLineTools
ruby -rrbconfig -e 'puts RbConfig::CONFIG["rubyhdrdir"]'
This should now correctly print
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/include/ruby-2.3.0
Likewise, gem install should work while that SDK is selected.
To switch back to using the current Xcode 11 SDK, use
sudo xcode-select --switch /Applications/Xcode.app
As of Xcode 11, it seems like the ruby development headers are no longer included, so you will need to manually install them outside of Xcode Command Line Tools.
E.g. for me using rbenv i did
rbenv install 2.6.4
rbenv global 2.6.4
eval "$(rbenv init -)"
Then ran bundle install and everything worked as expected.
I had the same problem while installing fastlane. The tadman's answer is correct, but the command lines don't work for me with Xcode 10.2.1 (I'm not sure with other versions). You need to open Xcode, then open Preferences, select Locations and choose Command Line Tools. In my case, Command Line Tools field is empty.
As @bdorfman said in his comment, the Ruby headers are no longer included as of Xcode 11 build but they seem to try to make a new build for this as soon as possible (?): https://discuss.circleci.com/t/xcode-11-gm-seed-2-released/32505/12.
What worked for me was to use rbenv like @bdorfman said:
rbenv install 2.6.4
rbenv global 2.6.4
eval "$(rbenv init -)"
But with the extra step of adding docker-sync to your new ruby version. Since after you change the ruby version (for example)
$ ruby -v
ruby 2.6.4p104 (2019-08-28 revision 67798) [x86_64-darwin18]
And then running gem list:
$ gem list
bigdecimal (default: 1.4.1)
bundler (default: 1.17.2)
cmath (default: 1.0.0)
csv (default: 3.0.9)
date (default: 2.0.0)
dbm (default: 1.0.0)
did_you_mean (1.3.0)
e2mmap (default: 0.1.0)
etc (default: 1.0.1)
fcntl (default: 1.0.0)
fiddle (default: 1.0.0)
fileutils (default: 1.1.0)
forwardable (default: 1.2.0)
io-console (default: 0.4.7)
ipaddr (default: 1.2.2)
irb (default: 1.0.0)
json (default: 2.1.0)
logger (default: 1.3.0)
matrix (default: 0.1.0)
minitest (5.11.3)
mutex_m (default: 0.1.0)
net-telnet (0.2.0)
openssl (default: 2.1.2)
ostruct (default: 0.1.0)
power_assert (1.1.3)
prime (default: 0.1.0)
psych (default: 3.1.0)
rake (12.3.2)
rdoc (default: 6.1.2)
rexml (default: 3.1.9)
rss (default: 0.2.7)
scanf (default: 1.0.0)
sdbm (default: 1.0.0)
shell (default: 0.7)
stringio (default: 0.0.2)
strscan (default: 1.0.0)
sync (default: 0.5.0)
test-unit (3.2.9)
thwait (default: 0.1.0)
tracer (default: 0.1.0)
webrick (default: 1.4.2)
xmlrpc (0.3.0)
zlib (default: 1.0.0)
(does not contains docker-sync)
If you run the gem install for docker-sync you will use the docker-sync for your rbenv managed ruby.
$ gem install docker-sync
If you want to get a deeper insight into the issue:
Mac OS X 10.14 has stopped placing the include libraries in their usual location, /usr/include, keeping them only inside the XCode directory.
To confirm that this is the problem, simply run
ls /usr/include. If the result comes out empty, its really this problem.Apple ships a “legacy installer” for you to be able to install the headers in the “old location”. To fix the problem just run this:
sudo installer -pkg /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg -target /
Open Terminal
xcode-select --install
sudo xcodebuild -license accept
curl -L https://get.rvm.io | bash -s stable
Close and Reopen Terminal
rvm install ruby-2.6
sudo gem install cocoapods
pod install
After completing right click on project top-left on android studio then click on Flutter -> Open IOS Module in Xcode
sudo xcode-select --installcommand says I already have Command-Line Tools installed. Also tried manually downloading Xcode 11 Command-Line Tools from Developer Downloads. But I still get the errormkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/include/ruby.h– jdelaune