Error installing puma (solved)

Hi Chris Oliver . When installing gems (on mac OS Big Sur) I got this:

Installing puma 4.3.0 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/.../jumpstart-pro-myapp/vendor/bundle/ruby/2.6.0/gems/puma-4.3.0/ext/puma_http11
/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 ./siteconf20201116-24090-pyul38.rb extconf.rb
checking for BIO_read() in -lcrypto... no
checking for BIO_read() in -llibeay32... no
creating Makefile

current directory: /Users/.../jumpstart-pro-myapp/vendor/bundle/ruby/2.6.0/gems/puma-4.3.0/ext/puma_http11
make "DESTDIR=" clean

current directory: /Users/.../jumpstart-pro-myapp/vendor/bundle/ruby/2.6.0/gems/puma-4.3.0/ext/puma_http11
make "DESTDIR="
compiling http11_parser.c
compiling io_buffer.c
compiling mini_ssl.c
compiling puma_http11.c
puma_http11.c:203:22: error: implicitly declaring library function 'isspace' with type 'int (int)'
[-Werror,-Wimplicit-function-declaration]
  while (vlen > 0 && isspace(value[vlen - 1])) vlen--;
                     ^
puma_http11.c:203:22: note: include the header <ctype.h> or explicitly provide a declaration for 'isspace'
1 error generated.
make: *** [puma_http11.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/.../jumpstart-pro-myapp/vendor/bundle/ruby/2.6.0/gems/puma-4.3.0 for
inspection.
Results logged to
/Users/.../jumpstart-pro-myapp/vendor/bundle/ruby/2.6.0/extensions/universal-darwin-20/2.6.0/puma-4.3.0/gem_make.out

An error occurred while installing puma (4.3.0), and Bundler cannot continue.
Make sure that `gem install puma -v '4.3.0' --source 'https://rubygems.org/'` succeeds before bundling. 

gem install puma -v '4.3.5'