# Unable to install "curb" gem on Big Sur

**URL:** <https://www.ruby-forum.com/t/unable-to-install-curb-gem-on-big-sur/262414>\
**Category:** Development\
**Created:** [January 15, 2022, 5:34pm UTC](https://www.ruby-forum.com/t/unable-to-install-curb-gem-on-big-sur/262414 "2022-01-15T17:34:26Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![YoungZeeZee](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/e19b73/32.png) [@YoungZeeZee](https://www.ruby-forum.com/u/YoungZeeZee)\
**Post date:** [January 15, 2022, 5:34pm UTC](https://www.ruby-forum.com/t/unable-to-install-curb-gem-on-big-sur/262414/1 "2022-01-15T17:34:26Z")

</div>

Hi All,

I am unable to install “curb” gem on Big Sur.  
Do you know how can i get it? I have curb (0.9.10) installed.

This is the error message:  
localadmin@MBA-C02FD4LCQ6L7 . % sudo gem install curb  
Password:  
Building native extensions. This could take a while…  
ERROR: Error installing curb:  
ERROR: Failed to build gem native extension.  
current directory: /Library/Ruby/Gems/2.6.0/gems/curb-1.0.0/ext  
/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 ./siteconf20220115-65608-88dplh.rb extconf.rb  
checking for curl-config… yes  
checking for curlopt\_tcp\_keepalive… \*\*\* 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/$(RUBY\_BASE\_NAME)  
–with-curl-dir  
–without-curl-dir  
–with-curl-include  
–without-curl-include=${curl-dir}/include  
–with-curl-lib  
–without-curl-lib=${curl-dir}/lib  
/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 extconf.rb:54:in `block in have_constant' 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 extconf.rb:46:in `have_constant' from extconf.rb:64:in `’  
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/curb-1.0.0/mkmf.log  
extconf failed, exit code 1  
Gem files will remain installed in /Library/Ruby/Gems/2.6.0/gems/curb-1.0.0 for inspection.  
Results logged to /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-20/2.6.0/curb-1.0.0/gem\_make.out  
localadmin@MBA-C02FD4LCQ6L7 . %