❯ nix-shell -p ruby

❯ uname -a
Darwin index.rubygems.org 21.1.0 Darwin Kernel Version 21.1.0: Wed Oct 13 17:33:23 PDT 2021; root:xnu-8019.41.5~1/RELEASE_X86_64 x86_64 i386 MacBookPro15,2 Darwin

❯ which ruby
/nix/store/6pmrf1633z5c9b73w6a8ah4h65gxhqvb-ruby-2.7.4/bin/ruby

❯ ruby --version
ruby 2.7.4p191 (2021-07-07) [x86_64-darwin17]

❯ which gem
/nix/store/6pmrf1633z5c9b73w6a8ah4h65gxhqvb-ruby-2.7.4/bin/gem

❯ gem install ddtrace -v '0.54.0' --source 'https://rubygems.org/'
Fetching msgpack-1.4.2.gem
Fetching ddtrace-0.54.0.gem
Fetching debase-ruby_core_source-0.10.12.gem
Building native extensions. This could take a while...
Successfully installed msgpack-1.4.2
Successfully installed debase-ruby_core_source-0.10.12
Building native extensions. This could take a while...
ERROR:  Error installing ddtrace:
	ERROR: Failed to build gem native extension.

    current directory: /Users/lang.sharpe/.local/share/gem/ruby/2.7.0/gems/ddtrace-0.54.0/ext/ddtrace_profiling_native_extension
/nix/store/6pmrf1633z5c9b73w6a8ah4h65gxhqvb-ruby-2.7.4/bin/ruby -I /nix/store/6pmrf1633z5c9b73w6a8ah4h65gxhqvb-ruby-2.7.4/lib/ruby/2.7.0 -r ./siteconf20211118-29473-1wrgai5.rb extconf.rb

+------------------------------------------------------------------------------+
| **Preparing to build the ddtrace native extension...**                       |
|                                                                              |
| If you run into any failures during this step, you can set the               |
| `DD_PROFILING_NO_EXTENSION` environment variable to `true` e.g.              |
| `$ DD_PROFILING_NO_EXTENSION=true bundle install` to skip this step.         |
|                                                                              |
| Disabling the extension will lead to the ddtrace profiling features not      |
| working in future releases.                                                  |
| If you needed to use this, please tell us why on                             |
| <https://github.com/DataDog/dd-trace-rb/issues/new> so we can fix it :)      |
|                                                                              |
| Thanks for using ddtrace! You rock!                                          |
+------------------------------------------------------------------------------+

creating extconf.h
creating Makefile

current directory: /Users/lang.sharpe/.local/share/gem/ruby/2.7.0/gems/ddtrace-0.54.0/ext/ddtrace_profiling_native_extension
make DESTDIR\= clean

current directory: /Users/lang.sharpe/.local/share/gem/ruby/2.7.0/gems/ddtrace-0.54.0/ext/ddtrace_profiling_native_extension
make DESTDIR\=
compiling clock_id_from_pthread.c
compiling clock_id_noop.c
compiling private_vm_api_access.c
private_vm_api_access.c:13:10: fatal error: 'rb_mjit_min_header-2.7.4.h' file not found
#include RUBY_MJIT_HEADER
         ^~~~~~~~~~~~~~~~
./extconf.h:4:26: note: expanded from macro 'RUBY_MJIT_HEADER'
#define RUBY_MJIT_HEADER "rb_mjit_min_header-2.7.4.h"
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
make: *** [Makefile:244: private_vm_api_access.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/lang.sharpe/.local/share/gem/ruby/2.7.0/gems/ddtrace-0.54.0 for inspection.
Results logged to /Users/lang.sharpe/.local/share/gem/ruby/2.7.0/extensions/x86_64-darwin-17/2.7.0/ddtrace-0.54.0/gem_make.out