bundle config build in Gemfile, or additional explanation to console after bundle fails?

[jspraul]

Can I set bundle config build.tiny_tds inside the Gemfile?

Setting the environment variable when running bundle works:

BUNDLE_BUILD__TINY_TDS=--with-freetds-include=/c/Ruby31-x64/msys64/ucrt64/include/freetds bundle

Setting the environment variable in the Gemfile does not work:

if RUBY_PLATFORM='x64-mingw-ucrt'
    ENV['BUNDLE_BUILD__TINY_TDS']='--with-freetds-include=/c/Ruby31-x64/msys64/ucrt64/include/freetds'
end

If this is not possible, is there a way to output additional help text after An error occurred while installing tiny_tds explaining exactly how to fix the issue?

[hsbt]

Can I set bundle config build.tiny_tds inside the Gemfile?

You cannot set it from the Gemfile, because Bundler reads BUNDLE_* from the environment before evaluating it. Use bundle config set --local build.tiny_tds ... instead.

is there a way to output additional help text after An error occurred while installing tiny_tds explaining exactly how to fix the issue?

There is also no hook for a gem to add help text to a failed build, so that has to come from the gem's own extconf.rb output.