Docker for Mac - mkmf.rb can't find header files for ruby

Question

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         


        

Answer 1

Single line command fix:

On OSX Mojave I ran the following command:

sudo installer -pkg /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg -target /

and it fixed the issue.

Answer 2

For Xcode 11 I fixed this by also installing of /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg package.

Answer 3

When upgrading XCode you need to install the Command-Line Tools and additionally accept the terms and conditions:

sudo xcode-select --install

Then:

sudo xcodebuild -license

Answer 4

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 /

https://silvae86.github.io/sysadmin/mac/osx/mojave/beta/libxml2/2018/07/05/fixing-missing-headers-for-homebrew-in-mac-osx-mojave/