Error installing CocoaPods - macOS BigSur

Question

I'm learning how to program, and I am trying to install Cocoapods, but I'm getting an error with sudo gem install cocoapods.

This is what I get:

    Building native extensions. This could take a while...
ERROR:  Error installing cocoapods:
    ERROR: Failed to build gem native extension.

    current directory: /Library/Ruby/Gems/2.6.0/gems/ffi-1.13.1/ext/ffi_c
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby -I /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0 -r ./siteconf20201006-615-fryp4a.rb extconf.rb
checking for ffi.h... *** 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=/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/$(RUBY_BASE_NAME)
    --with-ffi_c-dir
    --without-ffi_c-dir
    --with-ffi_c-include
    --without-ffi_c-include=${ffi_c-dir}/include
    --with-ffi_c-lib
    --without-ffi_c-lib=${ffi_c-dir}/lib
    --enable-system-libffi
    --disable-system-libffi
    --with-libffi-config
    --without-libffi-config
    --with-pkg-config
    --without-pkg-config
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:467:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:585:in `block in try_compile'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:534:in `with_werror'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:585:in `try_compile'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1109:in `block in have_header'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:959:in `block in checking_for'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:361:in `block (2 levels) in postpone'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:331:in `open'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:361:in `block in postpone'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:331:in `open'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:357:in `postpone'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:958:in `checking_for'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1108:in `have_header'
    from extconf.rb:10:in `system_libffi_usable?'
    from extconf.rb:42:in `<main>'

To see why this extension failed to compile, please check the mkmf.log which can be found here:

  /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-20/2.6.0/ffi-1.13.1/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /Library/Ruby/Gems/2.6.0/gems/ffi-1.13.1 for inspection.
Results logged to /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-20/2.6.0/ffi-1.13.1/gem_make.out

I know that there is a line where it says "You have to install development tools first", and at first it was true. I then installed the Xcode command line tools (I had to do it manually downloading it from Apple Developer because the xcode-select --install line didn't work), and tried to install cocoapods again. But I'm getting the same error, even after rebooting.

It also has the route for the log, and this is what it says:

package configuration for libffi is not found
"xcrun clang -o conftest -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/universal-darwin20 -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby/backward -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0 -I. -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -D_DARWIN_UNLIMITED_SELECT -D_REENTRANT    -g -Os -pipe -DHAVE_GCC_ATOMIC_BUILTINS -DUSE_FFI_CLOSURE_ALLOC conftest.c  -L. -L/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib -L. -L/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.0.Internal.sdk/usr/local/lib     -lruby.2.6   "
In file included from conftest.c:1:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby.h:33:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby/ruby.h:24:10: fatal error: 'ruby/config.h' file not found
#include "ruby/config.h"
         ^~~~~~~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/include/ruby-2.6.0/ruby/ruby.h:24:10: note: did not find header 'config.h' in framework 'ruby' (loaded from '/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks')
1 error generated.
checked program was:
/* begin */
1: #include "ruby.h"
2: 
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */

So, I'm stuck. I'm currently using macOS Big Sur Beta 9, and Xcode 12.0.1 (non-beta).

Answer 1

I had the same issue (Catalina 10.15.7 & Xcode 12.3).

I used homebrew instead of the gem:

brew install cocoapods