Ubuntu 24.04.2 LTSでう
$ /usr/bin/ruby -e 'p RUBY_DESCRIPTION, RubyVM.constants.find_all{|c| c =~ /JIT/}'
"ruby 3.2.3 (2024-01-18 revision 52bb2ac0a6) [x86_64-linux-gnu]"
[:MJIT]
$ ruby -e 'p RUBY_DESCRIPTION, RubyVM.constants.find_all{|c| c =~ /JIT/}'
"ruby 3.4.2 (2025-02-15 revision d2930f8e7a) +PRISM [x86_64-linux]"
[:YJIT, :RJIT]
gccが必要なのはMJITだったのかも←