You always want to know which versions of all the software involved in your build are being used. Having the environment cached contributes to you not knowing the versions being used in your build.
It would be great to list all those versions during a build phase. For instance, you could run
bundle list if
bundle check says it’s updated. Knowing OS, compiler, etc versions also helps.
I think it’s a really sane default to assume this while inferring commands.