Jekyll install on MacOS 11.1 still failing due to c++/cmath gem install error (sassc 2.4.0)

Jekyll install still fails on MacOS 11.1 (Big Sur) with clean installs of Ruby 3.0, XCode 12.3 and Command Line Tools 12.3.

According to the previous extensive discussion of this issue, it appears to be because of an include issue involving c++/cmath on Mac, but there still appears to be no reliable solution.

Deletion of Command Line Tools - a solution recommended in previous discussions of this issue - produces same result as output below.

Building native extensions. This could take a while...  ERROR:  Error installing jekyll:      ERROR: Failed to build gem native extension.        current directory: /usr/local/lib/ruby/gems/3.0.0/gems/sassc-2.4.0/ext  /usr/local/opt/ruby/bin/ruby -I /usr/local/Cellar/ruby/3.0.0_1/lib/ruby/3.0.0 -r ./siteconf20210117-30827-uvmn83.rb extconf.rb  creating Makefile    current directory: /usr/local/lib/ruby/gems/3.0.0/gems/sassc-2.4.0/ext  make "DESTDIR=" clean    current directory: /usr/local/lib/ruby/gems/3.0.0/gems/sassc-2.4.0/ext  make "DESTDIR="  compiling ./libsass/src/ast.cpp  In file included from ./libsass/src/ast.cpp:5:  In file included from ./libsass/src/ast.hpp:9:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/unordered_map:409:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__hash_table:18:  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:317:9: error: no member named 'signbit' in the global namespace  using ::signbit;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:318:9: error: no member named 'fpclassify' in the global namespace  using ::fpclassify;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:319:9: error: no member named 'isfinite' in the global namespace; did you mean 'finite'?  using ::isfinite;        ~~^  /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/math.h:752:12: note: 'finite' declared here  extern int finite(double)             ^  In file included from ./libsass/src/ast.cpp:5:  In file included from ./libsass/src/ast.hpp:9:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/unordered_map:409:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__hash_table:18:  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:320:9: error: no member named 'isinf' in the global namespace  using ::isinf;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:321:9: error: no member named 'isnan' in the global namespace  using ::isnan;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:322:9: error: no member named 'isnormal' in the global namespace  using ::isnormal;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:323:7: error: no member named 'isgreater' in the global namespace; did you mean '::std::greater'?  using ::isgreater;        ^~  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:738:29: note: '::std::greater' declared here  struct _LIBCPP_TEMPLATE_VIS greater : binary_function<_Tp, _Tp, bool>                              ^  In file included from ./libsass/src/ast.cpp:5:  In file included from ./libsass/src/ast.hpp:9:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/unordered_map:409:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__hash_table:18:  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:324:7: error: no member named 'isgreaterequal' in the global namespace; did you mean '::std::greater_equal'?  using ::isgreaterequal;        ^~  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:767:29: note: '::std::greater_equal' declared here  struct _LIBCPP_TEMPLATE_VIS greater_equal : binary_function<_Tp, _Tp, bool>                              ^  In file included from ./libsass/src/ast.cpp:5:  In file included from ./libsass/src/ast.hpp:9:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/unordered_map:409:  In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__hash_table:18:  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:325:9: error: no member named 'isless' in the global namespace  using ::isless;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:326:9: error: no member named 'islessequal' in the global namespace  using ::islessequal;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:327:9: error: no member named 'islessgreater' in the global namespace  using ::islessgreater;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:328:9: error: no member named 'isunordered' in the global namespace  using ::isunordered;        ~~^  /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:329:9: error: no member named 'isunordered' in the global namespace  using ::isunordered;        ~~^  13 errors generated.  make: *** [ast.o] Error 1    make failed, exit code 2    Gem files will remain installed in /usr/local/lib/ruby/gems/3.0.0/gems/sassc-2.4.0 for inspection.  Results logged to /usr/local/lib/ruby/gems/3.0.0/extensions/x86_64-darwin-20/3.0.0/sassc-2.4.0/gem_make.out  

https://stackoverflow.com/questions/65756644/jekyll-install-on-macos-11-1-still-failing-due-to-c-cmath-gem-install-error-s January 17, 2021 at 10:06AM