Bug #18249

Updated by Eregon (Benoit Daloze) over 1 year ago

In fact, in even conflicts with the next release's ABI version: 
 $ ruby -ve 'p RbConfig::CONFIG["ruby_version"]' 
 ruby 3.1.0dev (2021-10-11T10:13:16Z master 0c3ac87345) [x86_64-linux] 

 This mismatch can very easily result in segfaults, memory corruption, etc when using dev versions of CRuby, 
 or when using a dev version and then later the release. CRuby. 

 Possible solutions: 
 * Include the git commit sha in the ABI. Pros: always correct and simple. Cons: changing more then necessary. 
 * Track the ABI explicitly, and bump it whenever the ABI changes. Pros: changes only when needed. Cons: easy to forget bumping it, and if checked in CI already too late. 


 FWIW TruffleRuby actually tracks the ABI of dev versions through [this file]( which means it is possible to sensibly cache compiled gems even for dev versions [details]( 
 Also it [stores]( the ABI version in .so/.bundle files and checks them when loading, so it can be sure the ABI used to compile and runtime ABI match (if not, an exception is raised). 

 ruby/setup-ruby has no choice for CRuby dev but [to use the commit]( as the ABI version. 
 This issue is made worse by Ruby switchers like RVM & chruby setting GEM_HOME (so the ABI is effectively ignored by RubyGems in those cases, and those directories need to be cleaned manually). 
 When GEM_HOME is not set, it would be enough to rebuild CRuby dev and remove the directory before installing (which includes both CRuby & gems), but Ruby installers don't do that yet. 
 Bundler always includes the ABI version when setting the bundler path (`bundle config --local path`), but if the ABI version is incorrect like for CRuby dev it's of no use.