stringio 3.0.9 fails to install/compile on truffleruby-dev, RBASIC(strio)->flags

[eregon]

From ruby/openssl#699

$ gem i stringio
Fetching stringio-3.0.9.gem
Building native extensions. This could take a while...
ERROR:  Error installing stringio:
	ERROR: Failed to build gem native extension.

    current directory: /home/eregon/.rubies/truffleruby-dev/lib/gems/gems/stringio-3.0.9/ext/stringio
/home/eregon/.rubies/truffleruby-dev/bin/ruby extconf.rb
creating Makefile

current directory: /home/eregon/.rubies/truffleruby-dev/lib/gems/gems/stringio-3.0.9/ext/stringio
make DESTDIR\= sitearchdir\=./.gem.20231124-41381-hl1rfa sitelibdir\=./.gem.20231124-41381-hl1rfa clean

current directory: /home/eregon/.rubies/truffleruby-dev/lib/gems/gems/stringio-3.0.9/ext/stringio
make DESTDIR\= sitearchdir\=./.gem.20231124-41381-hl1rfa sitelibdir\=./.gem.20231124-41381-hl1rfa
compiling stringio.c
stringio.c: In function ‘readable’:
stringio.c:138:7: error: implicit declaration of function ‘RBASIC’ [-Werror=implicit-function-declaration]
  138 |     ((RBASIC(strio)->flags & STRIO_##mode) && \
      |       ^~~~~~
stringio.c:141:25: note: in expansion of macro ‘STRIO_MODE_SET_P’
  141 | #define READABLE(strio) STRIO_MODE_SET_P(strio, READABLE)
      |                         ^~~~~~~~~~~~~~~~
stringio.c:150:10: note: in expansion of macro ‘READABLE’
  150 |     if (!READABLE(strio)) {
      |          ^~~~~~~~

This is expected since #3118.
Fix for upstream in ruby/stringio#71

[eregon]

Fixed in stringio 3.1.0: ruby/stringio#71 (comment)

[eregon]

Unfortunately there is a rubygems.org issue currently which means stringio 3.1.0 might not be picked up in CI: rubygems/rubygems.org#4247

[eregon]

That rubygems.org issue is fixed now: rubygems/rubygems.org#4247 (comment)